Sergey Sibiryakov

Associate Professor, Physics & Astronomy

Academic background:

I graduated from the Moscow Institute of Physics and Technology in 2001 and completed my PhD at the Institute for Nuclear Research of the Russian Academy of Sciences (INR RAS) in 2004 under the supervision of Valery Rubakov. After a number of postdoctoral positions at INR RAS, European Center for Nuclear Research (CERN) and Ecole Polytechnique Fédérale de Lausanne (EPFL), I got in 2013 a joint fixed-term appointment at CERN and EPFL. In summer 2020 I moved to the Department of Physics and Astronomy at McMaster. I am also an associate faculty at the Perimeter Institute of Theoretical Physics in Waterloo, ON.

Research focus:

My research area is theoretical high-energy physics, broadly defined. I’m interested in the fundamental laws governing elementary particles and fields. A large part of my research is dedicated to open problems in gravitational physics and cosmology. These include the nature of dark matter and dark energy, origin and evolution of structures in the universe, formulation of the quantum theory of gravity.

General relativity (GR), which identifies gravity with space-time geometry, has been remarkably successful in explaining gravitational phenomena in many regimes from table-top experiments to astrophysics. However, combined with the principles of quantum mechanics, GR is doomed to fail at extremely short distances, where it must be substituted by a more fundamental description. Also at large distances comparable or bigger that the size of galaxies GR requires presence of mysterious dark matter and dark energy, to be compatible with observations.

This raises many fascinating questions shaping my research: What are dark matter and dark energy made of? How can we test various hypotheses from observations? What information is carried by the distribution of galaxies in the universe? What are the key features of quantum gravity? What are implications of quantum gravity for the physics of other fundamental forces?