## Ph.D positions available !!

Understanding the nature of dark matter, dark energy, the law of gravity or the origin of the structures we see today are among the most pressing questions in Cosmology.

I develop physical models and statistical methods for the formation and evolution of structures in the Universe, in order to properly interpret observational data, and maximize the information that can be extracted from future surveys.

Here are a few examples of recent work:

### Axion Dark Matter

If dark matter is in the form of very light, non-relativistic bosons such as axions, its large de Broglie wavelength (of Kiloparsec order) could alleviate the small-scale crisis of the popular Cold Dark Matter (CDM) model.

However, axions which acquired a mass through non-perturbative QCD effects are subject to an attractive self-interaction. This attractive force can counteract the “quantum pressure” induced by the strong delocalization and, furthermore, impact the stability of cosmic pancakes and filaments at low redshift.

### Shot noise & Cosmic variance

Both are an essential ingredient to the analysis of galaxy survey data. In particular, recent work has shown that the shot noise induced the Dark Matter halos hosting the galaxies becomes increasingly sub-Poissonian at high mass.

This effect can be understood with a suitably modified version of the halo model, which leads to meaningful predictions for the shot noise contributions to halo clustering statistics while removing the unphysical white noise present in other statistics. Model predictions can be tested with large numerical simulations of the CDM cosmology.

### Dynamical Friction

Dynamical friction (DF) is the gravitational drag force exerted on a perturber by the density wake it creates as it moves through a medium (stars, gas, dark matter etc.). DF is ubiquitous in cosmic structure formation (it controls the merger of compact or extended objects etc.)

Assuming linear response theory, we present an analytical solution to the DF force acting on circularly-moving perturbers in a gaseous environment. Our approach can be generalized to other media and (mildly) eccentric orbits.

## publications

A complete list of my publications can be found either on

SAO/NASA ADS or INSPIRE

All my open access publications can also be downloaded

from arXiv

## teaching

**Courses Taught:**

Analytical Mechanics

Galactic Dynamics

Large scale structure of the Universe

Mathematical methods for physicists

Physics of the Cosmic Microwave Background

Spacetime and Black Holes

**Spring semester 2023:**

### Quantum Mechanics 1

The course notes will be available at the Technion Moodle website.

A syllabus of the course can be found here.