Related papers: Kick it like DESI: PNGB quintessence with a dynami…
We consider a dark energy scenario driven by a scalar field $\phi$ with a pseudo Nambu Goldstone boson (pNGB) type potential $V(\phi)=\mu^4 \left( 1+ {\rm cos}(\phi/f) \right)$. The pNGB originates out of breaking of spontaneous symmetry at…
Supernova (SN) and baryon acoustic oscillation (BAO) distance measures have recently provided hints that the dark energy is not only dynamical but apparently evolves from normal to phantom dark energy between redshifts $0<z<1$. A normal…
We consider a 5-dimensional Ricci flat bouncing cosmological model in which the 4-dimensional induced matter contains two components at late times - the cold dark matter (CDM)+baryons and dark energy. We find that the arbitrary function…
We investigate the possibility that the dark matter abundance is sourced by the baryon/lepton asymmetry of the early Universe. It turns out that a Goldstone field of a local classically preserved symmetry in the Standard Model experiences a…
We propose a dark energy model in which a quintessence field $\phi$ rolls near the vicinity of a local maximum of its potential characterized by the simplest $S$ self-dual form $V(\phi) = \Lambda \ {\rm sech}(\sqrt{2} \, \phi/M_p)$, where…
Many models of meta-stable supersymmetry (SUSY) breaking lead to a very light scalar pseudo-Nambu Goldstone boson (PNGB), P, associated with spontaneous breakdown of a baryon number like symmetry in the hidden sector. Current particle…
We examine data from the Dark Energy Spectroscopic Instrument (DESI) collaboration which has implications for the nature of dark energy. We consider classes of models that manifestly obey the null energy condition, with a focus on…
In many well-motivated new physics models, the pseudo-Nambu-Goldstone boson (pNGB) from U(1) symmetry breaking emerges as a promising dark matter candidate. Its coupling, suppressed by the symmetry breaking scale, prevents thermal…
Non-supersymmetric Grand Unified $SO(10)\times U(1)_{\rm PQ}$ models have all the ingredients to solve several fundamental problems of particle physics and cosmology -- neutrino masses and mixing, baryogenesis, the non-observation of strong…
Is it possible that the current cosmic accelerating expansion will turn into a decelerating one? Can this transition be realized by some viable theoretical model that is consistent with the standard Big Bang cosmology? We study a class of…
Generalised axion-like scalar fields provide a well-motivated framework for describing the late-time acceleration of the Universe. As the field evolves, it rolls down its potential and, depending on its mass and initial conditions, it may…
We examine a quintessence model with a modified exponential potential given by $V(\phi) = V_0(1+e^{-\lambda \phi})$. Unlike quintessence with a standard exponential potential, our model can yield an acceptable accelerated expansion at late…
We introduce a natural model of quintessence in string theory where the light rolling scalar is radiatively stable and couples to Standard Model matter with weaker-than- Planckian strength. The model is embedded in an anisotropic type IIB…
We introduce a power-law parameterized quintessence model for the dark energy which accelerate universe at the low redshifts while behaves as an ordinary matter for the early universe. We construct a unique scalar potential for this…
We constructed a new class of inflationary model with the higher derivative axion field which obeys constant shift symmetry. In the usual axion (natural) inflation, the axion decay constant is predicted to be in the super-Planckian regime…
In axion quintessence, the cosmological era with an energy contrast in dark energy 0.1 < Omega_DE < 0.9 may represent a significant fraction of the universe's lifetime if the minimum of the axion potential is negative (unstable axion…
We develop a two-scalar field quintom model, which utilises both a quintessence-like and a phantom-like scalar field, enabling a smooth and stable transition across the $w=-1$ phantom divide as hinted by recent measurements of Baryonic…
We numerically investigate particle production by a pseudo-Nambu-Goldstone boson (pNGB) in spontaneous baryogenesis, focusing on large initial misalignment angles. Our analysis confirms the established cubic dependence of the baryon…
Spontaneous fission half-lives of actinide and super-heavy nuclei are calculated, using the least-action integral, through the WKB tunneling probability of the barrier that appears in the deformation landscape obtained in the…
The string inspired tachyon field can serve as a candidate of dark energy. Its equation of state parameter $w$ varies from 0 to -1. In case of tachyon field potential $V(\phi)\to 0$ slower(faster) than $1/\phi^2$ at infinity, dark…