Michael 'Misha' Rashkovetskyi

For a brief list of publications, see my ORCID, ADS or my Google Scholar profile.

Research projects

Selection/weighting of spectroscopic (DESI) galaxies based on thermal Sunyaev-Zeldovich map

(Prof. Daniel Eistenstein)

Goals:

Tools: Davis-Peebles estimator for the correlation function; efficient algorithm for finding close pairs in cylinders elongated along the line of sight

Semi-analytical covariance matrices for DESI 2-point correlation function

(Prof. Daniel Eistenstein, Prof. Hee-Jong Seo, Prof. Ashley Ross, Prof. Nikhil Padmanabhan)

Goal: produce independent covariance matrices for 2-point function for different Dark Energy Spectroscopic Instrument (DESI) datasets using RascalC code from Philcox et al 2020, Philcox et al 2019

Tools: importance sampling (Monte-Carlo) integration of analytical integrals, using interpolated 2-point correlation function; fitting to jackknife/mock covariance

Open source: further development version of RascalC (library), scripts including the DESI covariance pipeline

First-author publications:

Selected contributions:

Double-squeezed 4-point correlation function and squeezed 3-point correlation function

(Prof. Daniel Eistenstein)

Goals (potential):

Tools: efficient algorithm for alternatively binned quad/triple counting; numerical integration of disconnected 4-point function

Open source: 4/3/2-point function estimation code in $\mathcal O (N_{\rm galaxies}^2)$ time.

Inhomogeneous recombination relieving Hubble tension

(Prof. Daniel Eistenstein, Dr. Julian Munoz, Prof. Cora Dvorkin)

Goal: investigate the idea of relieving the Hubble tension with primordial magnetic fields, generalize and make forecasts

Tools: MCMC/nested sampling with Cobaya using CLASS Boltzmann code

Open source: modified CLASS with clumping models, mock CMB likelihood for Cobaya.

Publication: Michael Rashkovetskyi, Julian B. Muñoz, Daniel J. Eisenstein, and Cora Dvorkin, 2021. Small-scale clumping at recombination and the Hubble tension. Physical Review D 104.

The dynamics of highly magnetized jets propagating in the medium

(Dr. Omer Bromberg, Prof. Alexander Tchekhovskoy)

Goal: study their launching, propagation, instabilities, energy dissipation

Tools: GRMHD simulations in H-AMR code (improved version of HARM and harmpi)

My contribution: implementing the rotating perfect conductor BC, matter injection, grid modifications, tilting the jet to avoid pole singularity issues

Open source: harmpi with the neutron star boundary condition.

Pulsar losses mechanisms

(Prof. Vasily Beskin, Dr. Alexander Philippov)

Goal: understanding the reason of discrepancy between numerical simulations and theoretical considerations - the first give that total energy loss rate increases with inclination angle (between magnetic dipole and rotation axis), while the second gave the opposite trend

Key results: additional separatrix currents are important factor of radiopulsar losses reproduced in simulations; most of the energy starts flowing along open magnetic field lines already within the light cylinder; losses in numerical simulations are not dipolar

My contribution: analysis of electromagnetic field configuration in a force-free simulation snapshot; a method to separate polar cap from closed field lines region

Publication: V. S. Beskin, A. K. Galishnikova, E. M. Novoselov, A. A. Philippov, and M. M. Rashkovetskyi, 2017. So how do radio pulsars slow-down?. Journal of Physics Conference Series 932.

Orthogonal radiopulsars and their statistics

(Prof. Vasily Beskin, Egor Novoselov, Alisa Galishnikova, Dr. Anton Biryukov)

Goal: test two key models of radiopulsar period and inclination angle evolution (one theoretical by Beskin, Gurevich and Istomin (BGI) with one based on MHD and force-free simulations by Spitkovsky, Tchekhovskoy, Philippov and others) by predicting seen orthogonal pulsar numbers and comparing them to observed ones

My contribution: sampling pulsar distribution functions with Monte-Carlo simulation, making predictions based on it

Publication: E. M. Novoselov, V. S. Beskin, A. K. Galishnikova, M. M. Rashkovetskyi, and A. V. Biryukov, 2020. Orthogonal pulsars as a key test for pulsar evolution. Monthly Notices of the Royal Astronomical Society 494.

Open source: pulsar distribution sampling code.

Pulsar radiation propagation

(Prof. Vasily Beskin, Dr. Alexander Philippov)

Goal: understand the morphology of pulsar light-curves; find observational evidence of separatrix currents

Method: ray-tracing and integrating the polarization parameters according to Kravtsov-Orlov equation

Publication: H. L. Hakobyan, A. A. Philippov, V. S. Beskin, A. K. Galishnikova, E. M. Novoselov, and M. M. Rashkovetskyi, 2017. On the light-curve anomalies of radio pulsars. Journal of Physics Conference Series 932.

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