List of Publications on inSPIRE
List of Publications on Google Scholar
I obtained my BSc's degree from Physics department at Sharif university, Tehran. I received my PhD in physics from Brown University at 2005, followed by postdoctoral positions atUniversity of Wisconsin-Madison, Perimeter Instituteand University at Buffalo. I am now a faculty at Department of applied mathematics, University of Waterloo and affiliate member at Perimeter Institute.
My research has so far included tackling different aspects of theoretical cosmology such as investigating inflationary and bouncing scenarios, models of dark energy, modifications of general relativity, backreaction of metric perturbations, cosmic strings in extra dimensions and initial conditions for quantum fluctuations.
While mathematically intertwined, these research topics aim at understanding the theoretical puzzles about our cosmos in different phases of its evolution.
- Early Universe, the RightInitial Conditions
The physics of early universe is what determines how our cosmos looks like today.
An ideal theory of early universe would be well-motivated from our understanding of mathematical physics. It should not suffer from mathematical pathologies such as singularities or instabilities, it should set the right initial conditions for later stages of the cosmos without fine tuning, and also provide testable predictions that makes it falsifiable.
- Late Universe, Cosmological Constant problem and late time acceleration
The old cosmological constant problem is that large scale structures could not form in the cosmos if vacuum energy was not sixty orders of magnitude smaller than theoretical predictions. This alone had puzzled theoretical physicists across disciplines for many decades. For a long time, they were thinking there must be some underlying mathematical symmetry that forbids a non-zero vacuum energy. However, the discovery of late time acceleration of cosmic expansion by astrophysicists about a decade ago added a new twist to this problem. That vacuum energy is not actually zero just extremely small! This is now known as the new cosmological constant problem. Another aspect of this puzzle is known as coincidence or ``why now'' problem: Why is vacuum energy which is much smaller than theoretical predictions, just the right value to allow galaxies form first and then make the cosmic expansion accelerate?
