Related papers: Probing Leptogenesis and Pre-BBN Universe with Gra…
The scale of the seesaw mechanism is typically much larger than the electroweak scale. This hierarchy can be naturally explained by $U(1)_{B-L}$ symmetry, which after spontaneous symmetry breaking, simultaneously generates Majorana masses…
Leptogenesis is arguably the best motivated theory of baryogenesis given the discovery of finite neutrino masses, yet its experimental test is elusive given its high energy scale. We discuss gravitational waves (GWs) produced via graviton…
In seesaw mechanism, if right handed (RH) neutrino masses are generated dynamically by a gauged $U(1)$ symmetry breaking, a stochastic gravitational wave background (SGWB) sourced by a cosmic string network could be a potential probe of…
Gravitational-wave (GW) signals offer a unique window into the dynamics of the early universe. GWs may be generated by the topological defects produced in the early universe, which contain information on the symmetry of UV physics. We…
In type I seesaw models, the right-handed neutrinos are typically super-heavy, consistent with the generation of baryon asymmetry via standard leptogenesis. Primordial gravitational waves of cosmological origin provides a new window to…
Global cosmic strings are generically predicted in particle physics beyond the Standard Model, e.g., a post-inflationary global $U(1)$ symmetry breaking which may associate with axion-like dark matter. We demonstrate that although…
The dynamical generation of right-handed-neutrino (RHN) masses in the early Universe naturally entails the formation of cosmic strings that give rise to an observable signal in gravitational waves (GWs). Here, we show that a characteristic…
In a previous paper [1] we considered the possibility that (within the early-radiation epoch) there has been (also) a short period of a significant presence of cosmic strings. During this radiation-plus-strings stage the Universe…
Global cosmic strings are predicted in many motivated extensions to the Standard Model of particle physics, with close connections to axion dark matter physics. Recent studies suggest that, although subdominant relative to Goldstone…
In the past two decades, significant advancements have been made in observational techniques to enhance our understanding of the universe and its evolutionary processes. However, our knowledge of the post-inflation reheating phase remains…
The gravitational wave (GW) signals emitted by a network of cosmic strings are reexamined in view of the possible formation of a network of cosmic superstrings at the end of brane inflation. The reconnection probability $p$ of intersecting…
We analyze the damping of inflationary gravitational waves (GW) that re-enter the Hubble horizon before or during a post-inflationary era dominated by a meta-stable, right-handed neutrino (RHN), whose out-of-equilibrium decay releases…
We investigate a non-instantaneous reheating period in the early Universe, where the inflaton field decays exclusively to right-handed neutrinos (RHNs). The subsequent decay of these RHNs into Standard Model particles not only drives the…
We propose that a gravitational wave can be generated during leptogenesis in the early Universe which occurs when a heavy right handed neutrino decays out of equilibrium. Such a gravitational wave, as remnant of leptogenesis, is shown to be…
We discuss the damping of inflationary gravitational waves (GW) that re-enter the horizon before or during an epoch, where the energy budget of the universe is dominated by an unstable right handed neutrino (RHN), whose out of equilibrium…
The post-inflationary production of supermassive particles can have profound implications for the thermal history of the universe and may leave observable imprints in the gravitational wave (GW) background. In scenarios where the inflaton…
We revisit the hybrid inflation model gauged by $U(1)_{B-L}$ extension of the Minimal Supersymmetric Standard Model (MSSM) in a no-scale background. Considering a single predictive framework, we study inflation, leptogenesis, gavitino…
Breaking a global or local $U(1)_{\rm B-L}$ symmetry at high scales simultaneously generates Majorana masses for heavy right-handed neutrinos and produces a network of cosmic strings. The evolution and decay of these strings source a…
Spontaneous breaking of discrete symmetries like $Z_2$ leads to the formation of stable topological defects such as domain walls which, if allowed to dominate, can potentially be in conflict with cosmological observations. Incorporating…
We demonstrate that novel types of gravitational wave signatures arise in theories with new gauge symmetries broken at high energy scales. For concreteness, we focus on models with gauged baryon number and lepton number, in which neutrino…