A5054865216- Cosmology and Gravitation Theories
- Galaxies: Formation, Evolution, Phenomena
- Dark Matter and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Black Holes and Theoretical Physics
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Geophysics and Gravity Measurements
- Advanced Thermodynamics and Statistical Mechanics
- Optical measurement and interference techniques
- Gamma-ray bursts and supernovae
- Relativity and Gravitational Theory
- Theoretical and Computational Physics
- Calibration and Measurement Techniques
- High-Energy Particle Collisions Research
- Stellar, planetary, and galactic studies
- Structural Health Monitoring Techniques
- Ultrasonics and Acoustic Wave Propagation
- High-pressure geophysics and materials
- Electron and X-Ray Spectroscopy Techniques
- Earth Systems and Cosmic Evolution
University of Geneva
2024-2025
Institute for Nuclear Research
2015-2023
McMaster University
2021-2023
Perimeter Institute
2023
Moscow Institute of Physics and Technology
2015-2020
Russian Academy of Sciences
2016-2019
We present a new open-source code that calculates one-loop power auto- and cross-power spectra for matter fields biased tracers in real redshift space. These incorporate all ingredients required direct application to data: non-linear bias, redshift-space distortions, infra-red resummation, counterterms, the Alcock-Paczynski effect. Our is based on Boltzmann solver CLASS inherits its advantage: user friendliness, ease of modification, high speed, simple interface with other software. detailed...
We present a Markov-Chain Monte-Carlo (MCMC) forecast for the precision of neutrino mass and cosmological parameter measurements with Euclid-like galaxy clustering survey. use complete perturbation theory model one-loop power spectrum tree-level bispectrum, which includes bias, redshift space distortions, IR resummation baryon acoustic oscillations UV counterterms. The latter encapsulate various effects short-scale dynamics cannot be modeled within theory. Our MCMC procedure consistently...
It has been recently suggested~\cite{Berezhiani:2015yta} that emerging tension between cosmological parameter values derived in high-redshift (CMB anisotropy) and low-redshift (cluster counts, Hubble constant) measurements can be reconciled a model which contains subdominant fraction of dark matter decaying after recombination. We check the against CMB Planck data. find lensing anisotropies by large-scale structure gives strong extra constraints on this model, limiting as $F<8\%$ at...
We present limits on the parameters of o$\Lambda$CDM, $w_0$CDM, and $w_0 w_a$CDM models obtained from joint analysis full-shape, baryon acoustic oscillations (BAO), big bang nucleosynthesis (BBN) supernovae data. Our are fully independent data cosmic microwave background (CMB) anisotropies, but rival CMB constraints in terms parameter error bars. find spatial curvature consistent with a flat universe $\Omega_k=-0.043_{-0.036}^{+0.036}$ ($68\%$ C.L.); dark-energy equation state $w_0$ is...
An important aspect of large-scale structure data analysis is the presence non-negligible theoretical uncertainties, which become increasingly on small scales. We show how to incorporate these uncertainties in realistic power spectrum likelihoods by an appropriate change fitting model and covariance matrix. The inclusion error has several advantages over standard practice using sharp momentum cut ${k}_{\mathrm{max}}$. First, gradually suppresses information from short scales as employed...
We present the effective-field theory (EFT-)based cosmological full-shape analysis of anisotropic power spectrum eBOSS quasars at effective redshift ${z}_{\mathrm{eff}}=1.48$. perform extensive tests our pipeline on simulations, paying particular attention to modeling observational systematics, such as smearing, fiber collisions, and radial integral constraint. Assuming minimal $\mathrm{\ensuremath{\Lambda}}$ cold dark matter model, fixing primordial tilt physical baryon density, we find...
We study the implications of Planck temperature power spectrum at low multipoles, 0ℓ<100, and SPTPol data. show that this combination predicts consistent lensing-induced smoothing acoustic peaks within ΛCDM cosmology yields robust predictions cosmological parameters. Combining only large-scale data polarization lensing measurements model we found substantially lower values linear matter density perturbation σ8 which bring late-time parameter S8=σ8√Ωm/0.3=0.763±0.022 into accordance with...
A promising idea to resolve the long standing Hubble tension is postulate a new subdominant dark-energy-like component in prerecombination Universe which traditionally termed as early dark energy (EDE). However, shown Refs. [J. C. Hill et al., Early does not restore cosmological concordance, Phys. Rev. D 102, 043507 (2020), M. Ivanov al.,Constraining with large-scale structure, 103502 (2020).] cosmic microwave background (CMB) and structure (LSS) data impose tight constraints on this...
It has been recently suggested [1] that a subdominant fraction of dark matter decaying after recombination may alleviate tension between high-redshift (CMB anisotropy) and low-redshift (Hubble constant, cluster counts) measurements. In this report, we continue our previous study [2] the (DDM) model adding all available recent baryon acoustic oscillation (BAO) redshift space distortions (RSD) We find BAO/RSD measurements generically prefer standard $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$...
We provide a perturbative effective field theory (EFT) description for anisotropic (redshift-space) correlations between the Lyman alpha forest and generic biased tracer of matter, which could be represented by quasars, high-redshift galaxies, or dark matter halos. compute one-loop EFT power spectrum predictions combined analysis tracers' data test them on publicly available high fidelity Sherwood simulations. use massive light halos at redshift $z=2.8$ as proxies quasars respectively. In...
We study a model of keV-scale sterile neutrino with relatively large mixing the Standard Model sector. Usual considerations predict active generation such particles in early Universe, which leads to constraints from total Dark Matter density and absence X-ray signal decay. These bounds together may deem any attempt creation keV scale laboratory unfeasible. argue that for models hidden sector coupled these can be evaded, opening new perspectives direct studies at experiments as Troitsk...
We describe two new generation mechanisms for dark matter (DM) composed of sterile neutrinos with $\mathcal{O}(1)\text{ }\text{ }\mathrm{keV}$ mass. The model contains a light scalar field that coherently oscillates in the early Universe and modulates Majorana mass neutrino. In region parameter space, oscillations between active are resonantly enhanced. This mechanism allows us to produce neutrino DM small mixing angle neutrinos, thus evading x-ray constraints. At same time, spectrum...
The Dark Energy Spectroscopic Instrument (DESI) collaboration has recently released measurements of baryon acoustic oscillation (BAO) from the first year observations. A joint analysis DESI BAO, CMB, and SN Ia probes indicates a preference for time-evolving dark energy. We evaluate robustness this by replacing distance at $z<0.8$ with SDSS BAO in similar redshift range. Assuming $w_0w_a$CDM model, we find an evolution energy equation state parameters consistent $\Lambda$CDM. Our $\chi^2$...
We address the cosmological role of an additional ${\cal O}(1)$ eV sterile neutrino in modified gravity models. confront present data with predictions FLRW model based on a variant $f(R)$ proposed by one authors previously. This viable which deviation from general relativity constant $\Lambda$ decreases as $R^{-2n}$ for large, but not too large values Ricci scalar $R$ provides alternative explanation dark energy and accelerated expansion Universe. Various up-to-date sets exploited include...
It has been recently suggested [F. Bezrukov et al. J. Cosmol. Astropart. Phys. 06 (2017) 051; F. Rev. D 99, 083507 (2019)] that a cosmic scalar field can completely change the keV-scale sterile neutrino production in early Universe. Its effect may, for various parameter choices, either suppress and make moderate active-sterile mixing cosmologically acceptable, or increase generate considerable dark matter component out of with otherwise negligible SM. In this paper, we provide analytic...
We present new cosmological constraints in a set of motivated extensions the $\Lambda$CDM model using polarization and gravitational lensing measurements from South Pole Telescope Planck CMB temperature observations at large angular scales. In all scenarios, this data brings clustering into agreement with low-redshift probes large-scale structure. Combining SPT-3G, SPTpol latest full-shape BOSS BAO measurements, information weak photometric galaxy clustering, Pantheon supernova we find...
It was recently proposed [1] that the model with a fraction of decaying cold dark matter is able to reconcile measurements in high redshift (CMB) and low (probes cluster abundance Hubble constant). We check this statement employing full likelihood CMB Planck data. find lensing effect calculated from anisotropy spectra measured by imposes strong constraint on unstable as F < 8% (2σ). However, combining data conflicting we obtain ≈ 2 − 5% improves goodness-of-fit 1.5 2σ depending As τ priors...