At a Glance

Founded1986
Renewal dates1991, 1996, 2001, 2007, 2012
Members46
SupportersR. Howard Webster Foundation
Disciplines
Astrophysics; astronomy; astroparticle, computational, high energy and particle physics; observational cosmology

What is the nature of the universe?

Cosmology is at the root of some of the biggest questions in science. How did the universe begin? How did it evolve to its present form? What are the natures of dark matter and dark energy? Can we reconcile the seemingly contradictory worlds of quantum mechanics and general relativity?

Looking for answers to these fundamental mysteries helps us understand where we’ve come from and where we might be going, and allows us to study physics on scales too big for Earth-based laboratories.

Our unique approach

CIFAR’s Cosmology & Gravity program brings together some of the world’s most highly-regarded astronomers and cosmologists. The international team includes 45 leading experts in fields such as compact object physics, numerical relativity, string theory and particle astrophysics.

The program is deliberately broad in scope. It was founded on the belief that only by bringing together physical cosmologists, particle physicists, gravitational theorists, forefront observers and instrumentalists could progress be made in answering the deepest questions about the origin and evolution of the universe. This unique, multidisciplinary mix of theory and observation creates a fertile environment for new ideas.

Polarisation_of_the_Cosmic_Microwave_Background_zoom-WP
A visualisation of the polarisation of the Cosmic Microwave Background as detected by ESA’s Planck satellite on a small patch of the sky measuring 20º across. Image courtesy of the European Space Agency

Why this matters

In the 20th century, physics was dominated by two seemingly contradictory theories: quantum mechanics, which applies mainly to sub-atomic particles, and general relativity, which describes systems on a cosmic scale. Neither theory works well at the other’s scale, and so far all attempts to unify the two have failed. The quest for a “theory of everything” is one of the most important unsolved problems in physics.

CIFAR’s Cosmology & Gravity program began as an attempt to solve that problem. Since then it has expanded to tackle other unanswered questions about how galaxies form, the nature of dark energy and dark matter, the properties of fundamental particles, and the behaviour of matter in the most extreme environments in the Universe. A better understanding of the nature of the universe can help us grapple with the question of our own existence: is it the result of an extremely unlikely coincidence, or are the physical laws that allow our existence inevitable?

In depth

CIFAR’s unique team is able to take the models and hypotheses put forward by theorists and put them to the test using observations from advanced telescopes, including ground-based, balloon-borne and satellite observatories. Their work includes:

Theories of the early universe

A major focus of the Cosmology & Gravity program is on tracing the evolution of the early universe, from the Big Bang through its first several hundred thousand years. Some of the light from this period is still around today. Known as cosmic microwave background (CMB), it is found at outer reaches of the observable universe. Team members are using tools like the Planck space telescope or the BICEP2 collaboration at the South Pole to test the current thinking about this time period.

For example, a team that included Program Director J. Richard Bond, Senior Fellow Barth Netterfield, Associate Fellow George Efstathiou and Advisor Simon White recently published a set of papers which, among other things, showed that the first stars formed 140 million years earlier than was previously believed. They also showed that observations previously thought to be evidence of gravitational waves from a rapidly-expanding early universe were more likely caused by cosmic dust distorting the light.

The program also includes prominent theorists such as Senior Fellow Neil Turok. His novel cyclic model for cosmology, according to which the Big Bang is explained as a collision between two “brane-worlds”, is an alternative theory of early universe formation that could be tested by new observations.

Cosmic signposts

Another major area of research involves looking for cosmic signposts that can help researchers more accurately measure the size and shape of the universe, as well as the rate at which it is expanding. Researchers in this area include R. Howard Webster Foundation Fellow Victoria M. Kaspi, Senior Fellow Ray Carlberg, Senior Fellow Ingrid Stairs, Associate Fellow Wendy Freedman and many others. The signposts in question can be stars that vary their brightness at predictable intervals, such as pulsars. Comparing the brightness of these pulsing stars allows researchers to determine how quickly they are moving apart.

Stellar explosions like supernovae are the furnaces in which elements heavier than iron are born. A comprehensive survey of supernovae, carried out with the Canada-France-Hawaii telescope, offered new insights into the expanding universe and the distribution of matter within it.

Particle astrophysics

Canada is home to a unique piece of research equipment: an underground science laboratory called SNOLAB, located two kilometers below the surface in the Vale Creighton Mine near Sudbury, Ontario, Canada. The underground location shields the equipment from the cosmic radiation ubiquitous on the surface of the Earth, and allows it to more easily detect particles such as neutrinos. CIFAR members like Senior Fellow Mark Chen are collaborating with SNOLAB to learn more about neutrinos. These ghostly particles could offer clues about larger mysteries, including the nature of dark matter, the lack of antimatter  in today’s universe, and the validity of alternatives to the Standard Model  of particle physics.

Extreme environments

Neutron stars and black holes contain matter at incredibly high density, which in turn leads to enormous magnetic fields and powerful gravity. Theorists like Distinguished Fellow Werner Israel and Senior Fellow Matthew Choptuik build mathematical models that can tell us what happens to matter under these extreme conditions. These in turn shed light on the nature of gravity.

Next-generation instruments

CIFAR collaborations have been critical in bringing about some of the most significant “big science” projects in recent years. For example, Canada recently committed $243.5 million to construct the Thirty Meter Telescope, to be built on Hawaii’s Mauna Kea. Its mirror would be more than twice as wide as the largest telescopes operating today, offering an unprecedented ability to peer into the faintest corners of the universe. The seeds of Canada’s involvement in the project were sown in a CIFAR Cosmology & Gravity meeting more than ten years ago.

CIFAR fellows are driving development of a revolutionary new radio telescope called the Canadian Hydrogen Intensity Mapping Experiment (CHIME). It will observe radio waves at the 21 cm spectrum, building three-dimensional maps of the Universe and probing the mysteries of dark matter, as well as collecting observations of pulsars and newly discovered and mysterious objects known as fast-radio bursts. The telescope, under construction near Penticton, BC, consists of three stationary steel half-cylinders, each about 100 metres long and about 20 metres wide. As the Earth rotates the telescope sweeps the sky, collecting and analyzing radio waves with the help of specially designed electronics.

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Fellows in the program are deeply involved in building the revolutionary CHIME radio telescope in Penticton, BC, which will build three-dimensional maps of the universe

Antimatter has been created and manipulated in lab conditions. It consists of antiparticles, which have the same mass as their equivalents in ordinary matter, but the opposite charge, as well as other contrary quantum properties like spin. When a particle meets its antiparticle, it annihilates, sometimes forming neutrinos. According to leading theories, roughly equal amounts of matter and antimatter should have been created during the Big Bang. Yet today the universe is almost entirely made of matter, a major unsolved puzzle in physics.

The Standard Model is the traditional ‘recipe book’ for how to build our universe. It is a theory of particle physics that contains four fundamental forces —gravity, electromagnetism, strong nuclear force, weak nuclear force — and 17 subatomic particles, including quarks, electrons, photons, the Higgs boson and many others. It has been very successful at explaining most observable physical phenomena. However, it can only partially explain gravitation as explained by general relativity, and does not account for other phenomena, such as the accelerating expansion of the universe (hence the requirement for Dark Energy). A number of extensions which aim to bring the Standard Model more closely in line with observations have been proposed, including supersymmetry and string theory. Determining which of these would be the best improvement on the Standard Model is the goal of many theoretical and experimental physicists.

Selected papers

L. Kofman, A. Linde and A. Starobinsky, “Reheating after Inflation”, Physical Review Letters 73, 24 (Dec. 1994): 3195

V. Frolov and I. Novikov, Black Hole Physics, Springer Fundamental Theories of Physics series (1998).

Q.R. Ahmad et al, “Measurement of charged current interactions produced by 8B solar neutrinos at the Sudbury Neutrino Observatory,” Physical Review Letters 87, 7 (2001): 13 doi: http://dx.doi.org/10.1103/PhysRevLett.87.071301

The Planck Collaboration, “Planck 2013 results. I. Overview of products and scientific results,” Astronomy & Astrophysics 571 (2014).

Fellows & Advisors

Photo of J. Richard Bond

J. Richard Bond

Program Director

J. Richard Bond's theoretical work ranges from the ultra early to the ultra late universe, with influential works on the nature and behaviour of dark matter and energy, on inflation…

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Fellows

Lars Bildsten

Associate Fellow

University of California, Santa Barbara

United States

Raymond G. Carlberg

Senior Fellow

University of Toronto

Canada

Mark C. Chen

Senior Fellow

Queen's University

Canada

Matthew W. Choptuik

Senior Fellow

University of British Columbia

Canada

Andrew Cumming

Associate Fellow

McGill University

Canada

Matt Dobbs

Senior Fellow

McGill University

Canada

George P. Efstathiou

Associate Fellow

University of Cambridge

United Kingdom

Wendy Freedman

Associate Fellow

University of Chicago

United States

Carlos S. Frenk

Associate Fellow

Durham University

United Kingdom

Daniel Green

Fellow

University of Toronto

Canada

Mark Halpern

Senior Fellow

University of British Columbia

Canada

Gary Hinshaw

Senior Fellow

University of British Columbia

Canada

Henk Hoekstra

Associate Fellow

Leiden University

Netherlands

Gilbert Holder

Senior Fellow

McGill University

Canada

Werner Israel

Distinguished Fellow

University of Victoria

Canada

Shamit Kachru

Associate Fellow

Stanford University

United States

Nicholas Kaiser

Associate Fellow

University of Hawaii

United States

Renata Kallosh

Associate Fellow

Stanford University

United States

Victoria M. Kaspi

R. Howard Webster Foundation Fellow

McGill University

Canada

Luis Lehner

Senior Fellow

Perimeter Institute for Theoretical Physics and University of Guelph

Canada

Andrei Linde

Associate Fellow

Stanford University

United States

Arthur B. McDonald

Associate Fellow

Queen's University

Canada

Robert C. Myers

Senior Fellow

Perimeter Institute for Theoretical Physics

Canada

Julio F. Navarro

Senior Fellow

University of Victoria

Canada

Barth Netterfield

Senior Fellow

University of Toronto

Canada

John A. Peacock

Associate Fellow

The University of Edinburgh

United Kingdom

Ue-Li Pen

Senior Fellow

University of Toronto

Canada

Harald P. Pfeiffer

Fellow

University of Toronto

Canada

E. Sterl Phinney

Associate Fellow

California Institute of Technology

United States

Frans Pretorius

Associate Fellow

Princeton University

United States

Scott Ransom

Associate Fellow

National Radio Astronomy Observatory

United States

Joseph Silk

Associate Fellow

University of Oxford

United Kingdom

David Spergel

Associate Fellow

Princeton University

United States

Ingrid Stairs

Senior Fellow

University of British Columbia

Canada

Alexander S. Szalay

Associate Fellow

The Johns Hopkins University

United States

Neil Turok

Senior Fellow

Perimeter Institute for Theoretical Physics

Canada

William G. Unruh

Senior Fellow

University of British Columbia

Canada

Ludovic Van Waerbeke

Senior Fellow

University of British Columbia

Canada

Matias Zaldarriaga

Associate Fellow

Institute for Advanced Study

United States

Advisors

Roger Blandford

Advisor

Stanford University

United States

Richard S. Ellis

Advisor

University of College London

United Kingdom

Lyman Page

Advisor

Princeton University

United States

Eva Silverstein

Advisor

Stanford University

United States

Scott D. Tremaine

Advisory Committee Chair

Institute for Advanced Study

United States

Simon White

Advisor

Max Planck Institute for Astrophysics

Germany

Program Timeline

Program launches

CIFAR launches the program in Cosmology under the direction of

William Unruh wins gold medal

The Science Council of British Columbia awards Program Director William

Stephen Hawking joins CIFAR

World-renowned physicist Stephen Hawking joins CIFAR as an associate fellow

Classic cosmology paper presented at CIFAR

At the annual CIFAR Cosmology & Gravity program meeting, CIFAR

Program transforms cosmology research in Canada

The program is reviewed by an international panel of experts

Chaotic planetary orbit found

Program Director Scott Tremaine (Princeton University) finds that a recently

Black Hole Physics published

CIFAR Senior Fellow Valeri Frolov (University of Alberta) and Igor

D-branes advance string theory

Associate Fellow Robert Myers discovers a remarkable effect — the

BOOMERanG findings make global headlines

The BOOMERanG team publishes findings from its 1998 flight, which

Neutrinos discovered to have mass

CIFAR Fellow Mark Chen is part of the Sudbury Neutrino

Imager detects Universe’s “hot spots”

New data is unveiled from the international Cosmic Background Imager

BOOMERanG flies again

CIFAR Senior Fellow Barth Netterfield (University of Toronto) overseas another

Cosmic Background Imager analyzed new data

CIFAR researchers continue work on the reconfiguration of the Cosmic

First simulation of merging black holes

CIFAR Fellow Frans Pretorius (Princeton University) produces the first successful

Velocity of merged black holes predicted

CIFAR Fellow Frans Pretorius (Princeton University) makes significant progress in

Distant supernova helps scientists study dark energy

CIFAR Senior Fellow Raymond Carlberg (University of Toronto) leads an

Violent birth of a galaxy simulated

CIFAR Senior Fellow Hugh Couchman (McMaster University) and his team

Cosmic recycling discovered

R. Howard Webster Foundation Fellow Victoria Kaspi (McGill University) and

Accelerated expansion of the Universe confirmed

CIFAR Fellows Ludovic Van Waerbeke (University of British Columbia) and

First Planck telescope release

The European Space Agency’s Planck Telescope releases its first data

Galaxy simulations refined

Fellows Julio Navarro (University of Victoria), Hugh Couchman (McMaster University)

Early star formation measured through galaxies

Using the new Atacama Large Millimeter/submillimeter Array (ALMA) telescope, the

Triple-star system discovered

CIFAR fellows Ingrid Stairs (University of British Columbia), Victoria Kaspi

Planck results show stars were born later than thought

The European Space Agency’s Planck satellite makes the most precise

1986

Program launches

CIFAR launches the program in Cosmology under the direction of William Unruh (University of British Columbia). The program seeks to understand how the structure in the Universe we observe around us arose and developed in time. To do this, they aim to develop the quantum theory of gravity and other fields, essential ingredients to the generation and evolution of space-time, and use it to make predictions about the earliest micro-moments of the Big Bang. In addition, they intend to develop experiments and make observations to test these predictions. Fundamental questions that drive this research include how old the Universe is and how much mass it contains. The work has insights from new developments in such areas as pure and applied mathematics, statistics, computer science and philosophy, as well as physics and astronomy.

Credit: Wikimedia

1990

William Unruh wins gold medal

The Science Council of British Columbia awards Program Director William Unruh (University of British Columbia) the B.C. Science and Engineering Gold Medal in natural sciences. Unruh is lauded for his application of quantum field theory to black holes and for the Unruh effect, which states that the temperature of a moving thermometer in a vacuum is not zero.

Credit: Phil Plait / Flickr

An artist's illustration of a black hole

1990

A new view of black hole insides

CIFAR Senior Fellow Werner Israel (University of Victoria) finds that the warping of space-time near a black hole singularity does not necessarily vibrate wildly, catching all objects nearby and destroying them. He and his team finds that the warping may instead grow smoothly and continuously in a manner that is “null,” so that light signals can skim along the edge of the singularity and not be caught. The work leads to follow-up research by others that suggest the singularity inside a black hole may be chaotic when the hole is young, but evolve quickly into the smooth variety as the hole ages.

Credit: Wikimedia

Stephen Hawking at NASA in the 1980s

1992

Stephen Hawking joins CIFAR

World-renowned physicist Stephen Hawking joins CIFAR as an associate fellow in the Cosmology & Gravity program. He presents a CIFAR sponsored lecture at the University of Alberta on the future of the Universe, taking the stage with CIFAR fellows Werner Israel and Don Page. Hawking visits Edmonton on his way to participate in an international conference in honour of Israel, who is his close collaborator.

Credit: NASA/WMAP Science Team

An illustration of the expansion of the Universe dating back until inflation, with the WMAP satellite, launched in 2001

1994

Classic cosmology paper presented at CIFAR

At the annual CIFAR Cosmology & Gravity program meeting, CIFAR associate fellows Lev Kofman (Canadian Institute for Theoretical Astrophysics) and Andrei Linde (Stanford University) present their classic paper “Reheating After Inflation” for the first time. It remains one of the top-cited works in the field today, providing a new understanding of events in the earliest moments of the Universe.

1996

Program transforms cosmology research in Canada

The program is reviewed by an international panel of experts and renewed for the second time. It is deemed to have transformed cosmology research in Canada over the decade since its launch. During that period, the program focused on two related but distinct specialties: physical cosmology — the application of the laws of physics to study the origin and evolution of the Universe; and quantum gravity — the effort to marry Einstein's theory of general relativity with quantum mechanics. Canada ranks third in the world in theoretical cosmology, after the United States and the U.K., and the reviewers write that this is due in large part to the support and encouragement of CIFAR.

1996

Cosmological simulation code developed

CIFAR Senior Fellow Hugh Couchman (McMaster University) releases the first version of his cosmological simulation code called Hydra. Hydra helps scientists develop realistic numerical models of the formation of cosmic structures, such as galaxies and the first generation of stars. It becomes widely used worldwide.

1996

Scott Tremaine becomes director

Scott Tremaine (Princeton University) succeeds William Unruh as director of the program. Tremaine is regarded as one of the world’s best theoretical astrophysicists. Under his direction, the program’s name changes to Cosmology & Gravity, to better reflect the diversity of its research, and the fellows embark upon an ambitious plan to expand and diversify the program’s approach to understanding the cosmos.

1997

Chaotic planetary orbit found

Program Director Scott Tremaine (Princeton University) finds that a recently discovered planet around a star called 16 Cyg B has a highly irregular orbit pattern, and presents a theory to explain why. Tremaine and his colleagues suggest that the star’s companion star, 16 Cyg A, is exerting a constant gravitational pull that is changing the planet’s orbit. They posit that planets orbiting within two-star systems may sometimes collide with the primary star.

1998

Black Hole Physics published

CIFAR Senior Fellow Valeri Frolov (University of Alberta) and Igor Novikov publish the book Black Hole Physics, summing up the evidence from decades of theoretical research on the possibility that there are black holes — objects with a gravitational pull so strong that nothing, even light, can escape. Studying the physics of black holes has improved our understanding of much more than outer-space. It has tested our theories of space, time and gravitation.

Credit: Glenn Starkman

1998

Evidence that the Universe could be finite

CIFAR Associate Fellow Glenn Starkman (Case Western Reserve University) and collaborators find evidence contradicting previous assumptions that the Universe is infinite if it has a negative curvature. They find the Universe could be finite and small, in relative terms, even if its curvature is negative, and we could measure how big it really is. Understanding the Universe’s shape and size could help scientists work out how it was born and what happens in the moments afterward. If the Universe is smaller than the sphere of last scattering (where the cosmic microwave background originates), these intersections should be visible as circles of identical microwave background fluctuation on the sky.

1998

BOOMERanG’s first flight

The Balloon Observations Of Millimetric Extragalactic Radiation and Geophysics launches its first Antarctic flight, circling the South Pole for two weeks as it scans the sky to measure temperature fluctuations in the cosmic microwave background. CIFAR fellows J. Richard Bond (University of Toronto) and Barth Netterfield (University of Toronto) are involved in the project. The results of this flight, published in 2000, change our understanding of the Universe’s structure.

1999

D-branes advance string theory

Associate Fellow Robert Myers discovers a remarkable effect — the dielectric or "Myers" effect of D-branes. D-branes are extended objects that play a central role in our modern understanding of superstrings in string theory, which holds that the Universe is made of one-dimensional, vibrating strings at its smallest scale. Myers’ theoretical breakthrough is that D-branes swell in higher dimensions in the presence of applied fields.

2000

BOOMERanG findings make global headlines

The BOOMERanG team publishes findings from its 1998 flight, which indicate that the Universe is cosmologically flat. This finding is an important confirmation for the theory of inflation, which suggests the Universe underwent a period of exponential expansion in the moments after the Big Bang. Boomerang also indicates that the energy density of the Universe is dominated by Einstein’s cosmological constant, and that its mass is dominated by dark matter of some unknown form.  

2000

Radiation in black holes examined

CIFAR Fellow Don Page (University of Alberta) examines the puzzle of what would happen if a box of radiation were lowered very near the horizon of a zero-temperature (extreme) black hole. In theory, the black hole should allow all but an extremely small fraction of the box energy to be extracted. Then if the box were dropped in to the black hole with infinitesimal energy, it should increase the black-hole entropy — a measure of disorder — only very slightly, and yet the finite entropy of the radiation in the box should be lost. This seems to cause trouble for the second law of thermodynamics, which states that any cyclical process will lead the entropy to increase or remain the same. Page shows theoretically how to save the second law in this novel thought experiment.

2000

CMB photons point to Universe’s scale

CIFAR Program Director J. Richard Bond (University of Toronto) investigates constraints on the size of compact hyperbolic models of the Universe (those with negative curvature but finite volume) using observations of large-angle fluctuations in the cosmic microwave background radiation. He finds that the overall scale of the topology of the Universe must be about the size of the domain of last scattering of the CMB photons, otherwise the patterns in the CMB are incompatible with the observations.

2001

Neutrinos discovered to have mass

CIFAR Fellow Mark Chen is part of the Sudbury Neutrino Observatory (SNO) team, led by Advisor Arthur B. McDonald (Queen’s University), that solves a 30-year mystery about the properties of neutrinos, the billions of elementary particles of matter emitted by the nuclear reactions that fuel the sun. Particle properties are known to have deeply influenced the evolution of the Universe from its earliest moments into the present. Since the 1970’s, several experiments had detected neutrinos arriving on Earth, but had found only a fraction of the number expected according to detailed theories of energy production in the sun. The SNO team discovers that one type of neutrino that had seemed to be missing actually transforms into other neutrino types on the journey between the sun and the Earth. This discovery also indicates that neutrinos have mass, and will be very important in reaching a greater understanding of the Universe at the most microscopic level. In 2015, Arthur McDonald wins the Nobel Prize in Physics for this discovery.

2001

Team assembled for CMB theory

Program Director J. Richard Bond (University of Toronto), whose research interests are very broad, leads the assembly of a team for the theoretical analysis of fluctuations in the cosmic microwave background radiation, data that have major implications for the geometry of the Universe, for its contents of ordinary matter, dark matter, and dark energy, and for its ultimate fate.

2001

Universe weighed

Scientists estimate the Universe’s mass by studying the pattern of how hundreds of thousands galaxies cluster together. CIFAR associate fellows John Peacock (University of Edinburgh), George Efstathiou (University of Cambridge) and Richard Ellis (California Institute of Technology) are collaborators on the project, which confirms the standard model of cosmology — a flat, low-density Universe.

2002

Imager detects Universe’s “hot spots”

New data is unveiled from the international Cosmic Background Imager (CBI), located high in the mountains of Chile. The CBI is a highly sensitive 13-antenna device that makes images of the cosmic microwave background radiation. The new data provides a significant improvement in the angular precision of the primordial structures that grew about 14 billion years ago into the massive galaxies we see today and detects wavelengths that reveal radiation hot spots correlating to “clumps” of matter in an otherwise smooth Universe. These “clumps” eventually became clusters of galaxies. The data also provides insights into other major constituents of the Universe, including ordinary matter, dark matter and dark energy. CIFAR fellows J. Richard Bond, Ue-Li Pen and Barth Netterfield (all University of Toronto) are collaborators on the project.  

2003

BOOMERanG flies again

CIFAR Senior Fellow Barth Netterfield (University of Toronto) overseas another flight by the balloon-borne telescope BOOMERanG, which circles the South Pole for 13 days, scanning about 2,000 square degrees of the cosmic microwave background.

2003

Thirty Meter Telescope project established

An international partnership between four organizations commits to building the Thirty Metre Telescope on Mona Kea, Hawaii. The telescope is projected to be the most powerful optical telescope ever made. The four groups — the Association of Canadian Universities for Research in Astronomy, the California Institute of Technology, the University of California, and the (US) Association of Universities for Research in Astronomy, receive $10 million in funding from the Canada Foundation for Innovation. CIFAR Senior Fellow Raymond Carlberg (University of Toronto) is the project’s Canadian lead. For more information, please see the University of Toronto’s 2006 story about the project.  

2003

Theorists take on black strings

CIFAR Senior Fellow Matthew Choptuik (University of British Columbia) and collaborators complete an intense 18-month research project on unstable black strings. Black strings, like other models currently considered by theoretical physicists, exist in a Universe with greater than three spatial dimensions. The group directly simulates the dynamical behaviour of the black string, using large scale computer resources. The research provides intriguing hints of what the end state could possibly be like. Choptuik notes that CIFAR researchers William Unruh (University of British Columbia), Robert Wald (University of Chicago) and Advisor Gary Horowitz (University of California, Santa Barbara) played important roles in encouraging his team to take on the challenge of performing the difficult simulations required to shed light on this fascinating problem.

2004

Cosmic Background Imager analyzed new data

CIFAR researchers continue work on the reconfiguration of the Cosmic Background Imager (CBI) experiment in Chile, collecting new data since September 2002. Program Director J. Richard Bond (University of Toronto) and others provide new research insights and analyze stage of these experiments to determine whether the data agrees with theoretical predictions.

2004

Neutron stars reveal properties of condensed matter

CIFAR Fellow Andrew Cumming (McGill University) makes two important discoveries related to neutron stars in binary star systems, meaning two stars that orbit each other. When stars orbit each other, gravity produces a tidal effect on the stars’ gases, much like the ocean tides produced by the Moon’s orbit around the Earth. When a neutron star is paired in a binary system with a regular star, the tides on the regular star are so large that hydrogen and helium gases are stripped away and fall from the star onto the surface of the neutron star. There they are compressed and heated in the strong gravity for about a day before undergoing a spectacular thermonuclear runaway: thermonuclear reactions rapidly burn the gases into heavy elements, giving a bright burst of X-rays lasting tens of seconds. Detected by orbiting X-ray observatories, these bursts provide a brief but repeating glimpse of a neutron star’s surface. Cumming finds that the long X-ray bursts can be explained only if the neutrino emission is quite inefficient. He discovers a new way to probe the properties of matter compressed to densities much greater than anything on Earth.

2004

Neutron stars found to be hot and cold

CIFAR Fellow Andrew Cumming (McGill University) shows that the predicted winds on neutron stars are unstable, spontaneously breaking up into a pattern of bright hot and cold spots. The discovery provides an explanation for high frequency oscillations that had been detected in X-rays from neutron stars. These burning processes also happen in other situations in astronomy, but can be studied on short timescales because of the extreme physical conditions that exist on the surface of neutron stars.

2005

First simulation of merging black holes

CIFAR Fellow Frans Pretorius (Princeton University) produces the first successful numerical simulations of two black holes orbiting and finally merging with each other. Using new and original solution methods he is able to achieve a result that had eluded scientists for 40 years. Pretorius’s simulation makes it possible for scientists to predict the nature of gravitational waves emitted in black hole mergers and to help identify them. Once detected, these waves are expected to reveal information about the merged black holes they came from and potentially lead to major new insights into the workings of the Universe.

2006

Velocity of merged black holes predicted

CIFAR Fellow Frans Pretorius (Princeton University) makes significant progress in understanding how the strong gravitational fields around black holes warp space-time. His novel method predicts the velocity of a new black hole created by two black holes merging together. He predicts this velocity is caused gravitational waves pushing on the original black holes as they merge. He finds that velocities of 4000 km/s are possible, about 40 times more than thought possible in the past. He also explains why such great velocities are realistic — they are derived from the reserve of space-time energy the merging black holes carry around with them.

2006

Weak lensing makes dark matter measurable

CIFAR fellows Ludovic Van Waerbeke (University of British Columbia) and Henk Hoekstra (Leiden University) collaborate in a large, international project to obtain the most precise measurements of the distortion of light from distant galaxies due to the gravitational pull of intervening massive structures in the Universe. They use the largest ground-based surveys available to date (including the Canada-France-Hawaii Telescope Legacy Survey). The data allows them to measure the density of dark matter. For the first time, they are able to show results on the amount and distribution of dark matter in the Universe that is consistent with other observational probes.

2006

BLAST launches

The BLAST balloon-borne telescope launches from Antarctica. Scientists including Senior Fellow Barth Netterfield (University of Toronto) launch the highly sensitive bolometer and fly above the atmosphere to image radiation at sub-millimetre wavelengths, which cannot be detected as readily from the ground. In addition to leading the data analysis, Netterfield and other Canadian scientists build much of BLAST’s structure and instrumentation. Its first results are published in 2009.

2007

Distant supernova helps scientists study dark energy

CIFAR Senior Fellow Raymond Carlberg (University of Toronto) leads an international team of researchers working on the Canada-France-Hawaii Telescope Legacy Survey supernova program. The survey aims to distinguish between several competing theories to define the mysterious dark energy that is causing the expansion of the Universe to accelerate. Measuring the distances to observed supernova explosions becomes one of the main tools of choice for characterizing the effects and parameters of dark energy because it provides a reliable indicator of the Universe’s rate of expansion. Carlberg’s team devises a technique to discover the most distant supernovae ever seen, estimated to have occurred approximately 10 billion years ago. The technique involves adding together six months of images to create a very deep image of the sky. This allows the researchers to look for objects that changed in brightness over a long period of time. The survey results favour Einstein’s theory about the nature of the accelerating Universe, which has a parameter controlling this expansion known as the cosmological constant. The team reduces the statistical uncertainty on this parameter to only 4.4 per cent.

2008

Violent birth of a galaxy simulated

CIFAR Senior Fellow Hugh Couchman (McMaster University) and his team use state-of-the-art supercomputer simulations to model the formation of a small galaxy. The high-resolution simulations enable Couchman’s group to accurately model the very violent processes that galaxies suffer at their births. Dense gas clouds in the galaxy form massive stars, which, at the ends of their brief lives, blow up as supernovae. These huge explosions push the interstellar gas clouds back and forth in the centre of the galaxy. The group’s model shows that this “sloshing” effect — similar to water in a bathtub — kicks most of the dark matter out of the centre of the galaxy. This violent early history neatly solves the discrepancy between theory and observation of small galaxy formation, and exposes a critical relationship between gas and dark matter that was previously largely ignored.

2008

No black holes found in particle collisions

Calculations by CIFAR Senior Fellow Matthew Choptuik (University of British Columbia) and his team provide evidence against the theory that two particles colliding head-on at extremely high speeds, such as the collisions at the Large Hadron Collider, could create a tiny black hole. In fact, they suggest that particles might instead become relatively transparent to each other, so that they would effectively pass through one another during high energy collisions, emerging with their original identities largely intact. Choptuik collaborates with CIFAR Fellow Frans Pretorius (Princeton University) to extend and refine these calculations, previously limited to impact velocities significantly less than those that are encountered in the LHC.

M. W Choptuik and F. Pretorius, “Black hole production at LHC?” MPI-AEI, Golm, Germany, MPI-AEI Colloquium (April 30, 2008).

2008

First measurement of wobbling pulsar spin axis

R. Howard Webster Foundation Fellow Victoria Kaspi (McGill University) and colleagues confirm an important prediction of Einstein’s general theory of relativity using the now-famous “double pulsar” system. Pulsars are rotating neutron stars that emit beams of radio waves. The rotation creates a “lighthouse effect,” causing the source to appear to pulsate. The double pulsar system, discovered in 2003, is the first observed instance of two pulsars orbiting each other. Its brief orbit time of 2.4 hours, combined with its inherent pulsar properties, makes the double pulsar a particularly important test of relativity in a regime where it is a strong effect. Einstein’s theory predicts that the spin axis of at least one of the pulsars should precess (like a wobbling top) with time. Kaspi and her team makes the first quantitative measurement of this effect, showing that it agrees with Einstein’s theoretical prediction.

2009

Cosmic recycling discovered

R. Howard Webster Foundation Fellow Victoria Kaspi (McGill University) and her PhD student, Anne Archibald, discovers a “cosmic act of recycling.” They observe a dying pulsar that has very recently been brought “back to life” by drawing in material from a neighbouring star, thus increasing its own rotation speed. This transfer of material was first seen by an independent research group in 2000; however, they were not able to detect the pulsar, owing to the then in-falling material quenching the pulsar’s radiation. They find that nine years later, the pulsar is now “on” and spinning fast. Without such recycling, pulsars normally slow down as they age, and eventually disappear. But this lucky pulsar, though very old, was very much alive — extremely bright and spinning rapidly. Researchers had previously theorized that such recycling must take place, but no one had seen the process in progress.

Credit: ESA / C. Carreau

Artist's impression of the Planck spacecraft

2009

Planck launches

The Planck telescope is launched in 2009 to detect the Cosmic Microwave Background (CMB) – the cooled remnant of the first light of the Universe. The Planck mission involves Program Director J. Richard Bond and Senior Fellow Barth Netterfield (both University of Toronto), Associate George Efstathiou (University of Cambridge), and Advisor Simon White (Max Planck Institute for Astrophysics). The European Space Agency’s Planck project is at:  http://www.cosmos.esa.int/web/planck

2009

BLAST telescope reveals young stars

The BLAST balloon-borne telescope releases results from its Dec. 2006 flight. The telescope’s data includes the first-ever images of sub-millimetre radiation emitted from the clouds of gas and dust within which stars are formed. The dust absorbs starlight, hiding many young stars from view to the human eye. By imaging this dust in galaxies out to a distance of over 10 billion light years, the researchers are able to determine the location of the half of the starlight in the Universe that is obscured by dust. They plot out the history of star formation in the Universe over that critical very early period. The team also maps star formation in our own Milky Way galaxy in unprecedented detail over a wide range of evolutionary states.

2010

Accelerated expansion of the Universe confirmed

CIFAR Fellows Ludovic Van Waerbeke (University of British Columbia) and Henk Hoekstra (Leiden University) contribute to an international study that confirms that the rate of expansion of the Universe is accelerating, just as predicted by Einstein’s theory of general relativity. Cosmologists first observed this acceleration about a dozen years ago and worked towards understanding its source. Only about 5 per cent of the Universe is made up of “normal” matter as we know it and approximately 20 per cent is so-called “dark matter.” The international team’s findings result from an intensive study of over 446,000 galaxies detected in the largest-ever survey conducted by the Hubble Space Telescope, called COSMOS. Their study makes use of a technique called “weak gravitational lensing” pioneered by Van Waerbeke more than a decade ago. It allows researchers to infer the location of dark matter by observing how light travelling toward Earth from distant galaxies is distorted by the dark matter’s gravitational pull. The team is able to reconstruct a three-dimensional map of the dark matter in the study area and observe precisely how it evolved through the Universe’s history. The findings show for the first time that gravitational lensing is sensitive to the accelerated expansion of the Universe, independently from any other cosmological probe.

2010

Canadian Hydrogen Intensity Mapping Experiment is born

Fellow Ue-Li Pen (CITA/Toronto) and collaborators at Carnegie Mellon University and the Academia Sinica in Taiwan make pioneering observations using a new tool they developed for mapping large cosmic structures. Their technique, known as “intensity mapping,” holds the potential to shed light on the mysterious nature of dark energy. It maps and measures the radio frequency radiation emitted by hydrogen, the most plentiful element in the Universe. Their efforts lead to a new collaboration to map a large fraction of the Universe, called the Canadian Hydrogen Intensity Mapping Experiment, or CHIME, which involves researchers from across Canada, including Cosmology and Gravity Program Director and Fellow J. Richard Bond (CITA/Toronto) and Fellow Matt Dobbs (McGill).

2010

Unstable black holes’ behaviour probed

Fellow Luis Lehner (University of Guelph) and Fellow Frans Pretorius (Princeton University) develop a new supercomputer simulation that increases our understanding behaviour of how unstable black holes in higher dimensions behave. Lehner and Pretorius’ simulation show that a class of cylindrical black holes in higher dimensions cascaded into an infinite sequence of increasingly smaller spherical black holes connected by ever-thinning cylindrical black holes. The researchers calculate that this pattern eventually led to the development of a naked singularity when the cylindrical segments reach zero radius. A singularity is a “point” at the core of a black hole, where gravity becomes infinitely strong. The significance of the researchers’ finding was in violation of the “cosmic censorship conjecture,” which asserted that naked singularities should never form. This hypothesis fits within understandings of space-time proposed by the general theory of relativity — our modern theory of gravity. Yet, in extreme regimes like those around a singularity, this theory conflicts with the physics described by quantum mechanics. Thus, a naked singularity can expose a deep inconsistency in our understanding of the world.

2010

First discovery of a new pulsar

An international team of researchers, including R. Howard Webster Foundation Fellow Victoria Kaspi and Global Scholar Slavko Bogdanov (both McGill University), facilitates the first discovery of a new pulsar through a global volunteer computing initiative. Kaspi leads a group conducting a large-scale survey of pulsars in the Milky Way galaxy using the world’s largest radio telescope at the Arecibo Observatory in Puerto Rico. Pulsars are rather precise clocks and can be used to detect gravitational waves, a yet-to-be observed prediction of Einstein’s general theory of relativity. As more pulsars are discovered and monitored, the chance of detecting gravitational waves increases. Discerning pulsar signals from other radio waves picked up by the Arecibo telescope involved running complex algorithms that require significant computing resources. Kaspi’s group partners with the Einstein@Home initiative, which uses donated time from the home and office computers of 250,000 volunteers from 192 countries. The first detection of a pulsar through this program highlights the power of this form of computing and the potential of this survey for future discoveries.

Credit: Credit: European Space Agency

The microwave sky as seen by Planck.

2011

First Planck telescope release

The European Space Agency’s Planck Telescope releases its first data findings, including the discovery of 30 galaxy clusters and the detection of 15,000 sources of microwaves. Planck also discovers that a microwave fog covering our galaxy, the Milky Way, comes from fast-spinning dust grains in space.

2011

Lensing of Universe’s first light detected

The South Pole Telescope finds direct evidence that the Universe’s first light, or cosmic microwave background, is lensed, or bent, by dark matter and galaxies. The Atacama Cosmology Telescope also confirms the lensing, which is consistent with the theory of the cosmic web. This information can be used to constrain the Universe’s curvature and the nature of the dark energy. Global Scholar Keith Vanderlinde (University of Toronto) and Senior Fellows Matt Dobbs and Gilbert Holder (both McGill University) are collaborators on the South Pole Telescope.

2012

Galaxy simulations refined

Fellows Julio Navarro (University of Victoria), Hugh Couchman (McMaster University), Associate Fellow Carlos Frenk (University of Durham) and Advisor Simon White (Max Planck Institute for Astrophysics) take part in the “Aquila Project,” a comparison of state-of-the-art simulations of galaxy formation by 13 research groups around the world. Each group works with the same initial conditions for galaxy development, and they compare the findings of each group’s model, based on parameters such as star formation rates and galaxy size. The results provide valuable insights on how to improve the models such that they create and evolve galaxies that better match what we see in nature. The project reveals a considerable improvement in the degree to which scientists can simulate many gross properties of galaxies, owing to an increasing sophistication of numerical algorithms in the previous decade.

2012

Dark matter mapped

Using a camera on the Canada-France-Hawaii Telescope (CFHT), an international research team co-led by CIFAR Fellow Ludovic Van Waerbeke (University of British Columbia) culminates five years imaging 10 million galaxies located about six billion light years away. As light emitted by these galaxies travels to Earth, it becomes distorted or bent by the gravitational force of massive objects — such as clumps of dark matter — that it passes on the way. By analyzing the distortions in the CFHT images of these far-away galaxies, the researchers are able to infer the distribution of intervening dark matter. Their results showed that dark matter is spread like a web through the Universe — concentrated in large clumps and strands, with vast spaces in between. The clumps of dark matter coincide with clusters of galaxies, as predicted. The team’s findings bring us closer to understanding the nature of dark matter and its role in the Universe.

2013

Early star formation measured through galaxies

Using the new Atacama Large Millimeter/submillimeter Array (ALMA) telescope, the largest ground-based astronomical project in the world, an international research team measures the distance of several early galaxies. By measuring how far these galaxies are from Earth, astronomers can determine how soon after the Big Bang the Universe started making new stars. The team, which includes Global Scholar Keith Vanderlinde (University of Toronto) and Senior Fellows Matt Dobbs and Gilbert Holder (both McGill University), discovers the galaxies using the South Pole Telescope, and then analyzes them more closely with the Atacama Large Millimeter/ submillimeter Array (ALMA). They find that some of the galaxies are farther away than previously thought. Several were forming stars when the Universe was less than two billion years old — a billion years earlier than expected — while two were even more distant, creating stars just one billion years after the Big Bang.

Credit: European Space Agency

Cosmic microwave background seen by Planck (March 2013)

2013

Planck maps the early Universe

The Planck Space Telescope collaboration publishes results, providing researchers with the most precise view yet of the Universe soon after its birth. The telescope detects the Cosmic Microwave Background (CMB) — the cooled remnant of the first light of the Universe. This international collaboration reveals that our Universe is 13.82 billion years old — about 100 million years older than previously thought — and is expanding more slowly than previously determined by earlier, less-precise instruments. It also refines our understanding of the composition of the Universe, showing that it is made up of slightly more matter and slightly less dark energy than was measured by earlier experiments.

Credit: The CHIME collaboration

CHIME under construction in July, 2015

2013

Construction begins on CHIME

Canada begins construction on the Canadian Hydrogen Intensity Mapping Experiment (CHIME), a stationary telescope that will construct images from incoming radio waves. CIFAR fellows have contributed significantly to the design of CHIME, including Senior Fellow Matt Dobbs (McGill University), Program Director J. Richard Bond (University of Toronto) and several others. In addition to mapping the Universe, CIFAR’s R. Howard Webster Foundation Fellow Victoria Kaspi (McGill University), Senior Fellow Ingrid Stairs (University of British Columbia), and Associate Fellow Scott Ransom (National Radio Astronomy Observatory) collaborated with a team of CIFAR researchers to recognize that with only a small modification to the backend system, the telescope could simultaneously search for Fast Radio Bursts. Only a handful of these seemingly random bursts of radio waves of unknown origin have been detected, but the vast sky-scanning capacity of CHIME may help to discover many more, and more often.

2013

Dark matter mapped

CIFAR Senior Fellow Ludovic van Waerbeke (University of British Columbia) and CIFAR Associate Henk Hoekstra (Leiden University) use a technique called gravitational lensing to calculate the approximate mass of dark matter in regions of the universe where it is especially difficult to measure. Dark matter is invisible — it neither absorbs nor reflects light — therefore scientists must find it based on its effects on the matter we can see. The researchers, using data from the Canada France Telescope Lensing Survey, study how the light bends as it moves through the Universe to determine the mass of the dark matter through which it travels. They build maps of dark matter within super clusters of galaxies, voids in space and strings of matter between galaxies called bridges. In total, the maps cover 154 square degrees of area in the sky, almost 100 times larger than any previous dark matter map.

Credit: Bill Saxton/NRAO/AUI/NSF

Millisecond pulsar, left foreground, is orbited by a hot white dwarf star, center, both of which are orbited by another, more-distant and cooler white dwarf, top right

2014

Triple-star system discovered

CIFAR fellows Ingrid Stairs (University of British Columbia), Victoria Kaspi (McGill University) and others discover a unique triple-star system, offering the best opportunity to test a key tenet of Einstein’s theory of General Relativity. The stars include a white dwarf orbiting a pulsar, which together are orbited by a more distant white dwarf. While all these objects are collapsed remnants of exploded stars, the pulsar is much denser and emits lighthouse-like radio-wave beams as it spins on its axis. By timing these pulses with ultra-high-precision, the team calculates the system’s geometry and the stars’ masses with unprecedented accuracy. For more information, please see the University of British Columbia's news release.

Credit: Thirty Meter Telescope

Artist rendering of the proposed Thirty Meter Telescope

2014

Thirty Meter Telescope gets Canadian funding

The Thirty Meter Telescope project receives $25 million in Canadian funding. CIFAR Senior Fellow Raymond Carlberg (University of Toronto) serves as the Canadian project director. The project plans to build the first of the next generation of ‘super-sized’ telescopes, using new technology to decrease costs and enhance performance to study planets around other stars, galaxies in their earliest moments of formation, the super-massive black holes at the centres of galaxies, and the physics of the expansion of the Universe.

Credit: Arecibo Observatory/NSF

The Arecibo Observatory in Puerto Rico

2014

Fast Radio Bursts discovery confirms phenomenon

A burst of radio waves that have no clear origin but seem to have travelled across galaxies before arriving at our planet is discovered at the Arecibo Observatory in Puerto Rico by collaborators including CIFAR R. Howard Webster Foundation Fellow Victoria Kaspi (McGill University), Global Scholar Alumnus Slavko Bogdanov (Columbia University) and Senior Fellow Ingrid Stairs (University of British Columbia). Only a handful of other fast radio bursts have been detected previously, all of them by the Parkes radio telescope in Australia, with the first one reported in 2007. This is the first time that a different telescope has detected these same signals, bolstering evidence that they are not the result of equipment errors, but could be real and cosmic in origin.

Credit: European Space Agency

A map showing the polarization of the cosmic microwave background radiation

2015

Planck results show stars were born later than thought

The European Space Agency’s Planck satellite makes the most precise measurements of the polarization of the first light in the Universe, known as the cosmic background radiation, to date. The results show that the Universe forged its first stars 140 million years later than once thought, about 420 million years after the Big Bang. The new birth date aligns better with the rest of the Universe’s 13.8 billion-year history, including the formation of the first galaxies. Overall, the evidence by the Planck collaboration fleshes out a portrait of the early Universe that confirms the standard model of cosmology with more precision than ever before, from the Big Bang to an extremely rapid period of expansion called inflation, then to a long, slow process of cooling, expansion and formation of celestial bodies.

Credit: Lars Hagberg/Reuters

CIFAR Associate Fellow Arthur B. McDonald speaks on the phone shortly after learning that he was a co-winner of the Nobel Prize for Physics at his home in Kingston, Ontario October 6, 2015

2015

Arthur B. McDonald shares Nobel Prize in Physics

CIFAR Associate Fellow Arthur B. McDonald (Queen’s University), wins the Nobel Prize in Physics for his discovery that neutrinos change identities, a finding that showed these subatomic particles have mass. He shares the prize with Takaaki Kajita in Japan. McDonald led a research group including CIFAR Senior Fellow Mark Chen at the Sudbury Neutrino Observatory (SNO) that was studying neutrinos formed through nuclear reactions in the Sun. As these tiny particles travelled to Earth, two thirds of them seemed to be disappearing. McDonald’s group discovered that SNO was capturing the neutrinos, but they had changed identities from one to another of three different types. In order to make this change, the neutrinos must have mass.

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