280 papers
This paper demonstrates that an -corrected tachyonic scalar field inflation model with a rescaled Einstein-Hilbert term can successfully achieve a phantom divide line crossing and remain compatible with ACT data, provided the effective gravitational constant during inflation is stronger than standard Einstein-Hilbert gravity.
This paper establishes that perturbative unitarity in de Sitter spacetime, analyzed via momentum-space entanglement and purity in two-scalar models, imposes an upper bound on field-space curvature of the order of the Hubble scale—a constraint arising from the spacetime's thermal nature that complements traditional flat-space bounds.
This paper presents a dark fluid model described as a non-viscous, non-relativistic, rotating, and self-gravitating fluid with spherical symmetry and a polytropic equation of state, which is solved using a self-similar time-dependent ansatz to derive new solutions consistent with the Newtonian cosmological framework that can describe the transition from normal matter to dark energy on cosmological scales.
This paper employs Artificial Neural Networks and Bayesian Neural Networks to perform a model-independent calibration of Gamma-Ray Burst luminosity relations using observational Hubble parameter data, successfully resolving the circularity problem and yielding consistent Amati relation slopes that align with previous low-redshift calibrations.
This paper proposes and constrains a novel cosmological model where scalar field dark matter interacts with stepped dark radiation via pure momentum coupling, finding that while it offers marginal improvements over the original Wess-Zumino dark radiation model in alleviating the Hubble and tensions, it does not fully resolve these cosmological discrepancies.
Using the effective field theory of inflationary fluctuations, this paper explicitly proves for the first time that the renormalized one-loop power spectrum of the primordial curvature perturbation freezes exactly on super-horizon scales, thereby confirming the quantum-level validity of the conservation law essential for inflationary predictions.
This paper demonstrates that within the Effective Field Theory of inflation, one-loop gravitational corrections to primordial power spectra can be fully renormalized using dimensional regularization, resulting in exactly conserved scalar and tensor spectra on super-horizon scales and proving that propagation speeds remain immune to radiative corrections from gravitational nonlinearities.
This paper demonstrates that Model-Agnostic Meta-Learning (MAML) enables a cosmological emulator to rapidly adapt to new redshift distributions with minimal fine-tuning data, significantly outperforming standard single-task and non-pre-trained emulators in both accuracy and the fidelity of cosmological inference constraints.
This paper evaluates the performance of the Euclid Quick Data Release (Q1) spectroscopic processing function by comparing it with DESI survey data, demonstrating high redshift accuracy and precision while emphasizing the necessity of strict quality criteria to ensure an 89% success rate for cosmological targets in the $0.9 < z < 1.8$ range.
This paper investigates cosmological spacetimes where the spatial curvature is promoted to a time-dependent function, demonstrating that such sign-changing transitions—which allow for topological changes from closed to open universes while avoiding infinite initial energy densities—are consistent with global hyperbolicity under specific conditions and constructing three distinct geometries that exhibit these properties.
This paper forecasts that combining next-generation Type Ia supernova data from the Vera C. Rubin Observatory with BAO measurements from DESI and CMB data from advanced surveys will significantly improve constraints on dark energy parameters and enable a potential 2–3σ detection of the sum of neutrino masses, offering a powerful probe for physics beyond the standard cosmological model.
This paper presents a fully forward-modelled Bayesian framework for calibrating Milky Way Cepheids using Gaia EDR3 data, demonstrating that explicitly accounting for Galactic geometry and survey selection effects is essential to avoid biases in the period-luminosity relation and robustly support the local distance-ladder determination of .
This study utilizes the Jiutian-300 simulation and L-Galaxies 2020 model to demonstrate that incorporating realistic, time-varying star formation histories—specifically those dependent on stellar age and redshift—significantly alters the topology, timing, and thermal state of the Intergalactic Medium during the Epoch of Reionization, thereby producing distinct 21-cm global signals and power spectra compared to models assuming constant star formation rates.
Using a machine-learning-enhanced CatNorth quasar catalog and Planck CMB lensing data, this study derives low-redshift measurements that are generally consistent with the standard CDM model, thereby showing reduced evidence for the persistent tension compared to previous weak lensing results.
By combining a hybrid reconstruction of 65,518 galaxy peculiar velocities with 8,283 new redshifts—including 2,176 high-sensitivity HI measurements from the SARAO MeerKAT telescope to penetrate the southern Zone of Avoidance—this study reveals the Vela Supercluster as a dominant mass concentration rivaling the Shapley Concentration, thereby providing the most complete and dynamically consistent picture of the southern extragalactic sky to date.
This thesis utilizes strong gravitational lensing in the MACS J0416 field, combined with deep HST/JWST observations and machine learning to mitigate low-redshift interlopers, to test ultralight boson dark matter models and find no evidence for a faint-end turnover, thereby constraining the particle mass to be greater than $2.97\times10^{-22}$eV at 95% confidence.
This paper presents the Gravitational Waves-Lensing Mock Catalog (GW-LMC), a comprehensive suite of simulated strongly lensed gravitational wave events derived from a composite halo model, which forecasts hundreds of annual detections (including doublets, quadruplets, subhalo-lensed systems, and central images) for future third-generation ground-based detector networks and provides essential statistical priors for their identification.
This study demonstrates that void weak lensing, derived from the cross-correlation of cosmic voids and galaxy shear, provides a promising and independent constraint on the total neutrino mass with a linear signal-mass relationship, achieving a precision of eV in ideal conditions and $0.340$ eV under Stage-III-like noise levels.
Using exact non-Gaussian consistency diagnostics on CMB, BAO, and supernova data, this study finds that while Gaussian metrics may overstate tensions, both the standard CDM and its sign-switching extension CDM show excellent consistency between observations, with the latter offering modest geometric improvements at intermediate redshifts.
This paper utilizes near-Earth space-based measurements, including Gravity Probe B, LAGEOS-2, and prospective Sagnac interferometry with advanced clocks, to establish stringent bounds on chameleon, symmetron, and dilaton screened dark energy models, demonstrating that such experiments can exclude significant portions of their previously allowed parameter space.