宇宙学与河外天体物理
Measurements of thermodynamical quantities in galaxy clusters are differently affected by simplified modelling of radially averaged observables in the X-ray and millimetre bands. This includes assumptions about the cosmological model and…
The origins of the universe remain one of the biggest mysteries in modern cosmology. While the Planck satellite has provided a wealth of information about the early universe, there is still much to be discovered. The Square Kilometre Array…
Large imaging surveys in cosmology are detecting orders of magnitude more lens systems than known so far. This unprecedented dataset will lead to robust constraints on cosmology and galaxy evolution models. However, a preliminary careful…
The catalog from the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) Public Data Release 1 (PDR1) contains half a million emission-line-selected [OII] galaxies spread across $540~\mathrm{deg}^2$ at $z \le 0.48$ from HETDEX's…
We present a theoretical study of the non-linear evolution of cosmic voids -- underdense regions that occupy a large fraction of the observable Universe. We model a void as an isolated homogeneous spheroidal (axisymmetric) ellipsoid…
We introduce a framework to identify the radial transition in mass reconstruction reliability between strong and weak gravitational lensing in galaxy clusters. In weak lensing reconstruction, the convergence recovered from the reduced shear…
Suggestions of a late-time phantom crossing from DESI baryon acoustic oscillation measurements, combined with cosmic microwave background and Type-Ia supernova observations, have renewed interest in non-standard dark energy models. In this…
We present and validate a blinding method for the Lyman-$\alpha$ (Ly$\alpha$) forest analysis based on a modification of the Alcock-Paczynski test. In order to hide the background expansion history, the method employs a geometrical shift of…
Using the Cosmicflows-4 data, we reconstruct the first multipolar moments of a general function describing the local expansion rate. In addition to the conventional harmonic approach, we employ a basis of symmetric and trace-free tensors to…
Non-thermal synchrotron emissions from radio halo allow us to study mechanisms of particle (re)acceleration, magnetic field distribution, merger history, and turbulence in the intra-cluster medium. We propose power spectrum estimation as a…
We present an assessment of the current observational status of single scalar field models of dark energy. Motivated by recent cosmological measurements -- including baryon acoustic oscillations, Type Ia supernovae, and CMB data -- we…
The Dark Energy Survey (DES) provides optical data across 5000 square degrees of the southern sky, enabling a broad range of extragalactic and cosmological studies. Combining DES data with infrared surveys offers the opportunity to improve…
To best reproduce observed multiply-lensed lensed images, lens models usually incorporate shear attributed to objects unrelated to the lensing galaxy (i.e., external shear): whether it be neighbouring galaxies not explicitly included in the…
Star-forming galaxies are generally believed to be the main drivers of cosmic reionization. However, the relative contributions of bright and faint galaxies to this process remain unclear. As the most luminous transient phenomena in the…
We study the open quantum dynamics of the adiabatic curvature perturbation interacting with a massive entropic scalar environment during an inflationary scenario featuring a transient Ultra-Slow-Roll phase. Working within a Gaussian…
The DESI collaboration's Data Release~2 (DR2) provides baryon acoustic oscillation (BAO) measurements from over 14 million galaxies and quasars, and a joint analysis of DESI BAO, CMB, and Type~Ia Supernovae reveals a preference for…
Reconstructing the cosmic distance ladder directly from observations is a crucial issue in cosmology. In this paper, we present a novel method for modeling the cosmic distance ladder and estimating cosmological parameters through the use of…
We present a methodology for constructing a mock galaxy catalog for the All-sky SPECtroscopic survey of nearby galaxies (A-SPEC) using the Machine-assisted Semi-Simulation Model. The model is trained on the cosmological…
Gravitational waves from binary black hole mergers remain among primary sources for ground-based and space laser interferometers. Primordial binary black holes (PBHs) can form binaries in the early Universe or at the matter-dominated stage…
Recent baryon acoustic oscillation (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI), in combination with CMB and supernova data, show a mild preference for dynamical dark energy over flat $\Lambda$CDM. They can also…