Yadav, Anita Kumar, Suresh Kıbrıs, Cihad Akarsu, Özgür
Published in
Journal of Cosmology and Astroparticle Physics
In this work, we investigate a two-parameter extension of the ΛsCDM model, as well as the ΛCDM model for comparison, by allowing variations in the effective number of neutrino species (N eff) and their total mass (∑mν). Our motivation is twofold: (i) to examine whether the ΛsCDM framework retains its success in fitting the data and addressing major...
Kaci, Samy Giacinti, Gwenael
Published in
Journal of Cosmology and Astroparticle Physics
We present our new model for the description of the very high energy Galactic gamma-ray emission based on a discrete injection of cosmic rays by individual sources. We investigate the morphology of the very high energy gamma-ray sky, the detectability of cosmic-ray sources and the clumpiness of the diffuse gamma-ray flux, assuming two different sce...
Acharya, Sandeep Kumar Beniamini, Paz
Published in
Journal of Cosmology and Astroparticle Physics
We constrain the redshift dependence of (rest frame) host galaxy dispersion measures of localized Fast Radio Bursts (FRBs) by assuming it to vary as a simple power law (∝ (1+z) α ). We simultaneously fit α as well as the host dispersion measure to the data of FRBs with known redshifts. We find that α between 0 to 1 is preferred depending upon our m...
Melo-Carneiro, Carlos R. Furlanetto, Cristina Chies-Santos, Ana L.
Published in
Journal of Cosmology and Astroparticle Physics
Strong gravitational lensing and stellar dynamics are independent and powerful methods to probe the total gravitational potential of galaxies, and thus, their total mass profile. However, inherent degeneracies in the individual models makes it difficult to obtain a full understanding of the distribution of baryons and dark matter (DM), although suc...
Christiansen, Ø. Hassani, F. Mota, D.F.
Published in
Journal of Cosmology and Astroparticle Physics
A new degravitation mechanism within the framework of scalar tensor gravity is postulated and included by prescription. The mechanism eliminates all constant contributions from the potential to the Friedmann equation, leaving only the kinematic and the dynamic terms of the potential to drive cosmic acceleration. We explore a scenario involving a de...
Lehners, Jean-Luc Quintin, Jerome
Published in
Journal of Cosmology and Astroparticle Physics
Theoretical considerations motivate us to consider vacuum energy to be able to decay and to assume that the spatial geometry of the universe is closed. Combining both aspects leads to the possibility that the universe, or certain regions thereof, can collapse and subsequently undergo a curvature bounce. This may have occurred in the very early univ...
Moreno, Pablo Navarro Wojnar, Aneta Llanes-Estrada, Felipe J.
Published in
Journal of Cosmology and Astroparticle Physics
The Seidov limit is a bound on the maximum latent heat that a presumed first-order phase transition of neutron-star matter can have before its excess energy density, not compensated by additional pressure, results in gravitational collapse. Because latent heat forces an apparent nonanalytic behaviour in plots correlating physical quantities (kinks ...
Fortunato, Jéferson A.S. Bacon, David J. Hipólito-Ricaldi, Wiliam S. Wands, David
Published in
Journal of Cosmology and Astroparticle Physics
Fast Radio Bursts (FRBs) have emerged as powerful cosmological probes in recent years offering valuable insights into cosmic expansion. These predominantly extragalactic transients encode information on the expansion of the Universe through their dispersion measure, reflecting interactions with the intervening medium along the line of sight. In thi...
Erices, Cristian Fathi, Mohsen
Published in
Journal of Cosmology and Astroparticle Physics
In this paper, we find that unlike in General Relativity, the shift-symmetric subclass of Beyond Horndeski theories permits black holes with primary hair that are thermodynamically stable and align with current Event Horizon Telescope observations of the M87* and Sgr A* black holes. This work begins by investigating thermodynamic properties, analyz...
Cai, Rong-Gen Wang, Shao-Jiang Yuwen, Zi-Yan Zeng, Xiang-Xi
Published in
Journal of Cosmology and Astroparticle Physics
Recent reports of stochastic gravitational wave background from four independent pulsar-timing-array collaborations have renewed the interest in the cosmological gravitational wave background (CGWB), which is expected to open a new window into the early Universe. Although the early Universe is supposed to be extremely flat from an inflationary poin...
