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Michael 'Misha' Rashkovetskyi's research |
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For a brief list of publications, see my
- ORCID,
- NASA Astrophysical Data System search or ADS library,
- INSPIRE-HEP profile,
- Google Scholar profile.
(Prof. Daniel Eistenstein)
Goals:
- more precise inference of standard cosmological parameters: growth of structure, matter fraction, and neutrino masses
- testing modified gravity
- studying environmental effects on galaxy-halo connection
- systematic check for the tighter constraints from density-split and density-marked (density-weighted) clustering techniques
Tools: Davis-Peebles estimator for the correlation function; efficient algorithm for finding close pairs in cylinders elongated along the line of sight
(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:
- Michael Rashkovetskyi, Daniel Forero-Sanchez, Arnaud de Mattia, Daniel J. Eisenstein, Nikhil Padmanabhan, Hee-Jong Seo, Ashley J. Ross, et al., 2025. Semi-analytical covariance matrices for two-point correlation function for DESI 2024 data. Journal of Cosmology and Astroparticle Physics 2025.
- Michael Rashkovetskyi, Daniel Eisenstein, et al., 2023. Validation of semi-analytical, semi-empirical covariance matrices for two-point correlation function for early DESI data. Monthly Notices of the Royal Astronomical Society 524.
Selected contributions:
- Jeongin Moon, David Valcin, Michael Rashkovetskyi, Christoph Saulder, et al., 2023. First detection of the BAO signal from early DESI data. Monthly Notices of the Royal Astronomical Society 525.
- Daniel Forero-Sánchez, Michael Rashkovetskyi, Otávio Alves, et al., 2024. Analytical and EZmock covariance validation for the DESI 2024 results. arXiv e-prints.
- DESI Collaboration, et al., 2024. DESI 2024 III: Baryon Acoustic Oscillations from Galaxies and Quasars. arXiv e-prints.
- DESI Collaboration, et al., 2024. DESI 2024 II: Sample Definitions, Characteristics, and Two-point Clustering Statistics. arXiv e-prints.
- DESI Collaboration, et al., 2024. DESI 2024 V: Full-Shape Galaxy Clustering from Galaxies and Quasars. arXiv e-prints.
- DESI Collaboration, et al., 2025. DESI 2024 VI: cosmological constraints from the measurements of baryon acoustic oscillations. Journal of Cosmology and Astroparticle Physics 2025.
- DESI Collaboration, et al., 2024. DESI 2024 VII: Cosmological Constraints from the Full-Shape Modeling of Clustering Measurements. arXiv e-prints.
- DESI Collaboration, et al., 2024. The Early Data Release of the Dark Energy Spectroscopic Instrument. The Astronomical Journal 168.
- DESI Collaboration, et al., 2024. Validation of the Scientific Program for the Dark Energy Spectroscopic Instrument. The Astronomical Journal 167.
(Prof. Daniel Eistenstein)
Goals (potential):
- develop new prescriptions for non-gaussian higher-point functions for RascalC
- get halo occupation distribution constraints (following Yuan et al 2018)
- extend halo models to "proto-halos" at 10-30 Mpc scales (following Yuan et al 2017)
- probe primordial non-Gaussianity
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.
(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.
(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.
(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.
(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.
(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.