宇宙学与河外天体物理
Supermagnified stars, discovered by HST and JWST in lensing clusters of galaxies, are luminous stars in source galaxies lying near lensing caustics that are magnified by large factors ($\sim 1000$), making them detectable at cosmological…
Recent studies have revealed that the key properties of visible galaxies like their optical sizes, stellar ages, star formation rates and morphologies are closely linked with the angular momenta of their host dark matter halos. According to…
The string theory Swampland programme has resulted in distinct scenarios for the particle nature of dark matter. In this research note, I use combined cosmological probes to constrain the Dark Dimension scenario, which predicts that dark…
Cosmologically coupled black holes (CCBHs), whose masses evolve in response to the cosmological expansion, have recently attracted significant theoretical and observational interest. Existing studies have treated CCBHs as purely classical…
Due to their vast sizes and extremely low densities, the dynamics of cosmic voids are largely decoupled from complex, small-scale baryonic physics and are highly sensitive to the background expansion of the Universe. This makes them clean…
Cosmology stands at a crossroads. The Hubble tension has reached a nominal significance above $7\sigma$, while analyses combining DESI BAO and Type Ia supernova data show emerging hints of departures from $\Lambda$CDM. Meanwhile,…
The Hubble tension has reached a nominal significance above $7\sigma$, while new high-precision measurements of the cosmic microwave background (CMB) and baryon acoustic oscillations (BAO) sharpen the test of proposed solutions. Using a…
Active galactic nuclei (AGN) feedback via black hole-driven jets and winds plays a key role in redistributing matter across megaparsec scales. However, the implementation of jet feedback in cosmological simulations remains highly…
We investigate the late-time expansion history of the Universe using a model-independent spline reconstruction of cosmological distances based on the latest DESI DR2 baryon acoustic oscillation (BAO) measurements and the DES Dovekie Type Ia…
A non-minimal coupling between gravity and the inflaton field is a generic contribution in inflationary cosmology. In this work, we consider models of inflation with a non-minimal coupling $-\xi\phi^2 R$ and study their observational…
The SKA telescopes will revolutionise our ability to do cosmology at radio wavelengths, via both their own data and in synergy with other wavelengths. SKAO will be the first instrument able to conduct large-scale cosmological surveys as…
We investigate whether viable Hu-Sawicki-like $f(R)$ models can produce deviations from $\Lambda\mathrm{CDM}$ that can be tested against current background cosmological data. We adopt a machine-learning approach based on Genetic Algorithms…
The influence of dynamical (phantom) dark energy on light propagation within the framework of the Zeldovich-Kantowsky-Dyer-Roeder (ZKDR) approximation is discussed. This effect is considered in terms of the redshift-dependent parameter…
In this work, we constrain the phenomenological interacting dark energy $\xi$IDE model using baryon acoustic oscillation measurements from DESI Data Release 1 and Data Release 2, combined with cosmic chronometer measurements, compressed CMB…
Scalar field dark matter provides us with a well motivated alternative to conventional particle dark matter, especially when ultralight fields form coherent oscillations or compact self gravitating clumps. Here we develop three…
Although currently poorly constrained, cosmological ultra-large scales are expected to provide formidable tests not only of General Relativity, but also of the content of $\Lambda$CDM and the Early Universe. However, in this regime, cosmic…
Light but Massive Relics (LiMRs), cosmological relics that are relativistic at some point in the observable early universe but are non-relativistic today, are a generic prediction of many theories of physics beyond the Standard Model, and…
Massive fields exchanged during inflation source cosmological collider features in the correlators of primordial curvature fluctuations. While their structure is fixed by the symmetries of inflation, the amplitude of such signatures is a…
Cold Dark Matter predicts a population of low-mass halos which are sensitive to its fundamental nature and the primordial power spectrum, yet remain undetected. Although elusive, their discovery may be possible thanks to wave-optics lensing…
We present updated bounds on ultra-light axions (ULAs) as a subcomponent of dark matter, derived from the full-shape analysis of the DESI Data Release 1 galaxy power spectra combined with Cosmic Microwave Background (CMB) data from ACT and…