Prépublication
· 2026 arXiv
EN
If cosmic acceleration is driven by a positive cosmological constant, the universe approaches an eternally accelerating de Sitter state, whose interpretation in quantum gravity remains elusive. We develop a framework in which acceleration is instead a transien...
Gianmassimo Tasinato
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Prépublication
· 2026 arXiv
EN
Redshift space distortions (RSD) provide a powerful measurement of structure formation in modern cosmology. In this work, we explore the potential of 21cm intensity mapping with the MeerKAT Large Area Synoptic Survey (MeerKLASS) to detect RSD and probe gravity...
Daniel Tassie, Steven Cunnington et al.
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Prépublication
· 2026 arXiv
EN
The global topology of the Universe is a longstanding open question. In this work, we examine the statistical signatures of a positively curved universe with a Friedmann--Lemaitre--Robertson--Walker metric and the topology of a lens space $L(p,q)$. Since these...
Mikel Martin Barandiaran, Catherine Petretti et al.
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Prépublication
· 2026 arXiv
EN
We present the `Bias of Overdensities in Large-scale Tracers on the Sphere' (BOLTS) model, a novel analytic galaxy bias model for projected fields on the sphere that incorporates stochasticity and non-locality already at linear order while enforcing physicalit...
Maximilian von Wietersheim-Kramsta, Nicolas Tessore et al.
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Prépublication
· 2026 arXiv
EN
We report a direct measurement of the 21-cm signal from neutral hydrogen (HI) via the intensity mapping technique at redshift $z = 0.42$ through its power spectrum at cosmological scales $0.095\,h\,{\rm Mpc}^{-1}
MeerKLASS Collaboration, Matilde Barberi-Squarotti et al.
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Prépublication
· 2026 arXiv
EN
Supernovae (SNe) are excellent probes of the physical, chemical, and cosmological context of galaxies across the history of the Universe. The James Webb Space Telescope (JWST ) has a truly unique combination of wavelength, sensitivity, and resolution, providin...
Justin Pierel, David Coulter et al.
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Prépublication
· 2026 arXiv
EN
We constrain oscillatory features in the primordial power spectrum using the public DESI DR1 galaxy and quasar clustering data. Our analysis is based on a custom pipeline for the redshift-space power spectrum and bispectrum of the six main DESI DR1 tracers, mo...
Shi-Fan Chen, Anton Chudaykin et al.
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Prépublication
· 2026 arXiv
EN
We present the angular BAO analysis using DESI DR1 data as a complementary approach to DESI's primary 3D BAO analysis. We perform the analysis using the two-point angular correlation function $w(θ)$ in tomographic redshift shells of $δz = 0.02, 0.05$, spanning...
Anya Paopiamsap, Juan Mena-Fernández et al.
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Prépublication
· 2026 arXiv
EN
Recent cosmological constraints on the sum of neutrino masses have reached, and in some analyses fallen below, the minimum value implied by the normal mass ordering, suggesting a possible tension with neutrino-oscillation measurements. We investigate whether t...
Gabriel Rodrigues, Jamerson Rodrigues et al.
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Prépublication
· 2026 arXiv
EN
Cosmic birefringence, the rotation of the polarization plane of CMB photons, provides an intriguing probe of physics beyond the Standard Model. In this paper, we investigate a vector Chern-Simons coupling between the neutrino current and photons as a possible...
Kentaro Kasai, Ippei Obata
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Prépublication
· 2026 arXiv
EN
We present a low entry barrier numerical code LazyTB that solves the Einstein equations in the ADM-formulation for a general spherically symmetric problem with an arbitrary number of fluids with user defined equations of state and optional interactions between...
Kimmo Kainulainen, Enrico Schiappacasse et al.
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Prépublication
· 2026 arXiv
EN
Cosmological first-order phase transitions can generate curvature perturbations through inhomogeneous quantum tunneling, as studied previously on superhorizon scales. In this work, we for the first time conduct three-dimensional lattice simulations that incorp...
Yuan-Jie Li, Jing Liu et al.
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