research assistant at Rudolf Peierls Centre for Theoretical Physics, Oxford, UK (since 2015)
researcher at Tamm Theory Department of the Lebedev Physical Institute, Moscow, Russia (since 2003)
postdoc at Rochester Institute of Technology, Rochester, NY, USA (2011–2012)
PhD in theoretical physics (2007) from LPI;
graduated from Moscow Institute of Physics and Technology in 2003.
Phone: +7(499)132-6172; email: email@example.com
Dark matter halo structure and evolution
The evolution of dark matter in central areas of galaxies is considered (Milky Way is taken as an example). The formation of a galaxy leads to the compression of dark matter halo due to baryonic infall. Traditional method of calculating the compression (Blumenthal method) is shown to overestimate the dark matter density, especially for more flat initial halo density profiles and for radially anisotropic particle velocities. Subsequent evolution is driven by scattering off of dark matter particles on bulge stars and their absorption by the supermassive black hole. It is described by diffusion equation in energy - angular momentum phase space. The diffusion coefficients are calculated, as well as the absoroption and evaporation rate of particles. It is shown that by now the density of dark matter inside central parsec is greatly diminished: approximately 10% of initial dark matter mass is captured by black hole, about a half is evaporated. The annihilation of particles may explain observed gamma-ray flux from Galactic center
Its results are mainly presented in the following papers:
E.Vasiliev, M.Zelnikov, "Dark matter dynamics in the galactic center" (Phys.Rev.D 2008)
Stellar dynamics around supermassive black holes, in particular:
Structure of non-spherical nuclear star clusters containing black holes and the rates of star consumption by SMBH
K.Lezhnin, E.Vasiliev, "Tidal disruption rates in non-spherical galactic nuclei formed by galaxy mergers" (submitted)
Orbits around black holes in triaxial nuclei (poster at the Dynamics and evolution of disc galaxies conference, June 2010, Moscow/Pushchino)
Структура орбит в ядрах галактик и "кормление" сверхмассивных чёрных дыр (talk at Sternberg Astronomical Institute, April 2010)
Relaxation and black hole feeding rates in non-spherical galactic nuclei (talk at the Dynamics of Galaxies conference, May 2012, Sochi)
Supermassive black holes in non-spherical galactic nuclei and enhanced rates of star capture events (talk at CITA and the Perimeter Institute, Waterloo, September 2012)
Сверхмассивные чёрные дыры и темп захвата звёзд в несферических ядрах галактик (talk at LPI, January 2013)
LOSSCONE — a set of programs to compute the rates of star captures by supermassive black holes.
Interaction of a spinning supermassive black hole with the surrounding stellar cluster
Resonant relaxation around supermassive black holes
Резонансная релаксация в окрестностях сверхмассивных чёрных дыр (a review talk at LPI, June 2010)
Evolution of binary supermassive black holes
E.Vasiliev, "Evolution of binary supermassive black holes and the final-parsec problem" (proceedings of the IAU312 symposium "Black holes and star clusters in galaxies across cosmic time, August 2014, Beijing)
Binary supermassive black holes and the final-parsec problem (talk at University of Waterloo, September 2012)
Evolution of binary supermassive black holes: the final-parsec problem (talk at LPI, December 2013)
Life and adventures of binary supermassive black holes (review talks at LPI, Marseille and Rome, March-May 2014)
Evolution of binary supermassive black holes and the final-parsec problem (talk at the IAU312 symposium "Black holes and star clusters in galaxies across cosmic time, August 2014, Beijing), and an updated version presented at Albert Einstein Institute (Potsdam), November 2014
Evolution of binary supermassive black holes: the final-parsec problem is solved (talk at LPI, April 2015)
Evolution of binary supermassive black holes and the mythical final-parsec problem (talk at MODEST-15s meeting in Kobe and at HEA-2015 conference in Moscow, December 2015)
Life and adventures of binary supermassive black holes (colloquium at UNAM, Mexico, June 2016)
Dynamical modelling of galaxies:
Schwarzschild modelling of triaxial stellar systems, possibly containing supermassive black holes:
SMILE — a software for orbit analysis and Schwarzschild modelling of triaxial stellar systems.
New variants of Schwarzschild modelling (poster at The great Andromeda galaxy conference, June 2012, Princeton)
Orbit analysis of N-body simulations and galactic models (talk at UChicago, October 2012)
Weighting supermassive black holes (a review talk at LPI, June 2013)
Orbit analysis and Schwarzschild modelling of triaxial stellar systems (talk at MPIA/Heidelberg, November 2013)
Dynamical modelling of galaxies (lecture at the DAGal summer school, Marseille, June 2014)
Schwarzschild orbit superposition method for disc galaxies (talk at the Gaia Challenge 2, Heidelberg, October 2014)
Regular and chaotic dynamics of triaxial galaxies, evolution induced by chaotic orbits
E.Athanassoula, M.Romero-Gomez, E.Vasiliev, "Chaos in galaxies" (a short literature overview for IAU transactions, 2011)
Регулярность и хаос в звёздной динамике (a review talk at LPI, November 2008)
Chaotic mixing and the secular evolution of triaxial cuspy galaxy models built with Schwarzschild's method (poster at the Assembling the puzzle of Milky Way conference, April 2011, France)
Chaos and secular evolution of triaxial elliptical galaxies (talk at RIT, February 2011)
The role of chaos in secular evolution of galaxies (talk at Institut Henri Poincare, November 2013)
Agama — action-based galaxy modelling library.
N-body simulations of self-gravitating systems (galaxies, nuclear star clusters)
Secular Monte-Carlo method (poster at Institut Henri Poincare, November 2013)
A new Monte-Carlo method for dynamical evolution of non-spherical stellar systems (talk at the MODEST-14 meeting, June 2014, Bonn)
Monte-Carlo methods in stellar dynamics, in application to massive black holes in galactic nuclei (talk at LPI, September 2014)
Raga — a software for Monte Carlo simulations of non-spherical stellar systems, possibly containing massive black holes.
A number of useful standalone programs for creating and analyzing N-body snapshots are distributed with SMILE, in particular:
mkspherical — create spherical isotropic mass models with a given arbitrary density profile, or analyze dynamical properties of a spherically-symmetrized approximation to a given N-body snapshot;
measureshape — measure the shape (axis ratio) of an N-body snapshot as a function of radius.
Introduction and tutorial for gravitational N-body simulations (for undergraduates, Spring 2013): Lecture notes and problems.
Lecture 1: Astrophysical introduction to gravitational dynamics.
Basic concepts: mean-field regime, two-body relaxation, collective effects, secular evolution.
Physical regimes: collisional vs. collisionless.
Overview of gravitational N-body problem, computational challenges.
Astrophysical contexts: planetary systems, star clusters, galactic dynamics, cosmological structure formation.
Lecture 2: Collisional systems — planetary systems and star clusters.
Direct-summation methods. Symplectic and Hermite integration methods. Choice of timestep.
Two-body regularization schemes and their extensions.
Secular evolution of near-Keplerian systems, orbit-averaged approach.
Long-term evolution of planetary systems and globular clusters.
Lecture 3: Collisionless systems — galaxies and cosmology.
Force softening and its physical interpretation; resolution and convergence.
Tree-code and fast multipole methods.
Grid-based Poisson solvers (FFT and multigrid relaxation methods), adaptive mesh refinements schemes.
Basis-set expansion technique.
Cosmology: comoving coordinates, initial conditions, halo finders.
Lecture 4: Unconventional approaches and miscellaneous other issues.
Computational issues: hardware acceleration, GPU, parallelization strategies.
Direct solution of collisionless Boltzmann equation, applications to dark matter dynamics in cosmology.
Fokker-Planck and Monte Carlo methods for collisional systems.
Hydrodynamics — main approaches: grid-based, SPH, moving-mesh.
Gastrophysics and sub-grid physics in cosmological context.
Seminar 1: Overview of gravitational N-body simulation software.
Workflow of numerical simulations. Individual simulation codes and integrated frameworks: NEMO, Starlab, AMUSE.
Architecture of the AMUSE framework. Setting up and testing the simulation environment on laptops.
Creating and analyzing a simple N-body model.
Seminar 2: Simulations of collisional systems.
First-hand experience with various integration schemes. Assessing the validity of simulations, error control.
Evolving a star cluster and the Solar system.
Seminar 3. Simulations of collisionless systems.
Dynamical friction acting on a point-mass satellite orbiting in a galaxy.
Seminar 4. Bridge coupling of individual integrators.
Star cluster orbiting in a galaxy. Tidal stripping and dissolution acting together with dynamical friction.
Е.Васильев, "Тёмная материя и тёмная энергия во Вселенной" (a short review paper, 2008)
Тёмная материя и тёмная энергия во Вселенной (a review talk, April 2008)
Introduction to cosmology (3rd year undergraduates, semestral class). Lecture presentations (in russian):
Summary of recent results (2009–2011, in russian).