Related papers: Multifaceted Supercooling: From PTA to LIGO

Cosmological phase transitions in the primordial universe can produce anisotropic stochastic gravitational wave backgrounds (GWB), similar to the cosmic microwave background (CMB). For adiabatic perturbations, the fluctuations in GWB follow…

We present a catalog of gravitational wave background (GWB) signal templates from cosmic-string networks, based on relevant models proposed in the literature. We classify templates as conventional, based on standard cosmology and Nambu-Goto…

Forthcoming advances in direct gravitational wave detection from kilohertz to nanohertz frequencies have unique capabilities to detect signatures from or set meaningful constraints on a wide range of new cosmological phenomena and new…

One of the primary gravitational wave (GW) sources for pulsar timing arrays (PTAs) is the stochastic background formed by supermassive black holes binaries (SMBHBs). In this paper, we investigate how the environments of SMBHBs will effect…

First-order phase transitions produce gravitational waves and primordial black holes. They always occur in field theories where symmetries are radiatively broken and masses are correspondingly generated. These theories predict a period of…

If supersymmetry is broken in metastable vacua, it is not clear why we are now in there rather than supersymmetric vacua. Moreover, it is natural to expect that we were in supersymmetric vacua, which have higher symmetry than metastable…

Pulsar-timing arrays (PTAs) are in the near future expected to detect a stochastic gravitational-wave background (SGWB) produced by a population of inspiralling super-massive black hole binaries. In this work, we consider a background that…

Gravitational Waves (GW) sourced by second-order primordial curvature fluctuations are among the favored models fitting the recent pulsar timing array (PTA) measurement of a stochastic GW background (SGWB). We study how spectral distortions…

The cosmic string is a useful probe of the early Universe and may give us a clue to physics at high energy scales where any artificial particle accelerators cannot reach. Although one of the most promising tools is the cosmic microwave…

Recently, pulsar timing array (PTA) experiments have provided compelling evidence for the existence of the nanohertz stochastic gravitational wave background (SGWB). In this work, we demonstrated that cosmic string loops generated from…

A stochastic gravitational-wave background (SGWB) is expected to arise from the superposition of many independent and unresolved gravitational-wave signals, of either cosmological or astrophysical origin. Some cosmological models…

Several pulsar timing array (PTA) experiments such as NANOGrav and PPTA recently reported evidence of a gravitational wave (GW) background at nano-Hz frequency band. This signal can originate from scalar-induced gravitational waves (SIGW)…

Pulsar Timing Arrays (PTAs) have reported evidence for a stochastic gravitational wave (GW) background at nHz frequencies, possibly originating in the early Universe. We show that the spectral shape of the low-frequency (causality) tail of…

A stochastic gravitational wave background (SGWB) would gravitationally lens the cosmic microwave background (CMB) photons. We find that the lensing due to gravitational waves(GW) is more efficient as compared to lensing due to scalar…

We investigate the properties of gravitational waves generated by heating induced phase transitions in warm inflation. In this scenario, the heating phase of inflation followed by subsequent cosmological cooling can trigger two associated…

Production of gravitational waves in the early universe is discussed in a cosmologically consistent analysis within a first order phase transition involving a hidden sector feebly coupled with the visible sector. Each sector resides in its…

We present a Fisher-matrix forecast for the detectability of a stochastic gravitational wave background generated by a first-order phase transition in the early universe. We use the DECIGO and LISA missions as reference cases. The source…

The NANOGrav, Parkes and European Pulsar Timing Array (PTA) experiments have collected strong evidence for a stochastic gravitational wave background in the nHz-frequency band. In this work we perform a detailed statistical analysis of the…

Pulsar Timing Arrays (PTAs) have recently found strong evidence for low-frequency gravitational waves (GWs) in the nanohertz frequency regime. As GWs pass, they produce deviations in measured lengths and light-travel times. PTA experiments…

Cosmic strings are predicted in various extensions of the Standard Model, including grand unified theories. Depending on the symmetry-breaking pattern, they can be either topologically stable or metastable. Intriguingly, metastable strings…