Related papers: Primordial Magnetogenesis and Gravitational Waves …
Axion-like particles (ALPs) rotate the linear polarization of photons through the ALP-photon coupling and convert the cosmic microwave background (CMB) $E$-mode to the $B$-mode. We derive the relation between the ALP dynamics and the…
Axion-like particles (ALPs) and photons can quantum mechanically interconvert when propagating through magnetic fields, and ALP-photon conversion may induce oscillatory features in the spectra of astrophysical sources. We use deep (370 ks),…
In this thesis, we aim to investigate the mechanisms underlying the genesis of magnetic fields in the Universe and explore their potential in addressing the matter-antimatter asymmetry. We construct consistent models that generate the…
The axion-like particle (ALP)-photon mixing in the magnetic field around $\gamma$-ray sources or along the line-of-sight could induce oscillation between photons and ALPs, which then causes irregularities in the $\gamma$-ray spectra. In…
Polarimetric features during the prompt phase of Gamma-ray Bursts (GRBs) have been essential for elucidating the debated emission mechanisms and gaining insight into the inner structure of GRBs. However, the potential impact of…
Axion Like Particles (ALPs) are predicted to couple with photons in the presence of magnetic fields. This effect may lead to a significant change in the observed spectra of gamma-ray sources such as AGNs. Here we carry out a detailed study…
We demonstrate that enhanced early galaxy formation can generically arise in axion-like particle (ALP) dark matter (DM) models with a delayed onset of axion field oscillation. In these models, the formation of localized massive objects…
Axion-Like Particles (ALPs), if exist in nature, are expected to mix with photons in the presence of an external magnetic field. The energy range of photons which undergo strong mixing with ALPs depends on the ALP mass, on its coupling with…
Axion-like particles (ALPs) are very light, neutral, spin zero bosons predicted by many theories which try to complete the standard model of elementary particles. ALPs interact primarily with two photons and can generate photon-ALP…
The presence of non-zero helicity in intergalactic magnetic fields (IGMF) has been suggested as a clear signature for their primordial origin. We extend a previous analysis of diffuse Fermi-LAT gamma-ray data from 2.5 to more than 11 years…
Axion like particles (ALPs) are fundamental pseudo scalar particles with properties similar to Axions which are a well-known extension of the standard model to solve the strong CP problem in Quantum Chromodynamics. ALPs can oscillate into…
In this work, we present a lattice study of an axion - dark photon system in the early Universe and show that the stochastic gravitational wave (GW) background produced by this system may be probed by future GW experiments across a vast…
A first-order phase transition in the early universe can give an observable stochastic gravitational background (SGWB), which will necessarily have primordial anisotropies across the sky. In multi-field inflationary scenarios, these…
Axion-like particles (ALPs), predicted in theories beyond the Standard Model, can have observational effects on the transparency of the Universe to $\gamma$ rays in the presence of magnetic fields. In this work, we search for effects…
Experimental refinements and technical innovations in the field of extensive air shower telescopes have enabled measurements of Galactic cosmic-ray interactions in the sub-PeV range, providing new avenues for the search for new physics and…
Many theories beyond the Standard Model of particle physics predict the existence of axionlike particles (ALPs) that mix with photons in the presence of a magnetic field. Searching for the effects of ALP-photon mixing in gamma-ray…
We propose a scenario of primordial gravitational atoms (PGAs), which may exist in the current and past universe due to spinning primordial black holes (PBHs) and very light bosonic fields. In a monochromatic mass scenario with a sizable…
Ultralight axionlike particles (ALPs) are compelling dark matter candidates because of their potential to resolve small-scale discrepancies between $\Lambda$CDM predictions and cosmological observations. Axion-photon coupling induces a…
Gravitational waves (GWs) produced during first-order phase transitions (FOPTs) in the early universe provide a powerful probe of nonstandard cosmological histories. We study GW production from a FOPT ending a kination-dominated epoch in…
Large scale magnetic fields seem to be present in almost all astrophysical systems and scales from planets to superclusters of galaxies and in very low density intergalactic media. The upper limit of primordial magnetic fields (PMF) has…