Related papers: From NANOGrav to LIGO with metastable cosmic strin…
Gravitational waves from cosmic strings are generated in the first fractions of a second after the Big Bang, potentially providing a unprecedented probe of the early universe. We discuss the key dynamical processes underlying calculations…
Recently, multiple pulsar timing array collaborations have presented compelling evidence for a stochastic signal at nanohertz frequencies, potentially originating from cosmic strings. Cosmic strings are linear topological defects that can…
We propose a diagnostic tool for future analyses of stochastic gravitational wave background signals of extra-galactic origin in LISA data. Next-generation gravitational wave detectors hold the capability to track unresolved gravitational…
Inflationary string cosmology backgrounds can amplify perturbations in a more efficient way than conventional inflationary backgrounds, because the perturbation amplitude may grow - instead of being constant - outside the horizon. If not…
The NANOGrav pulsar timing array experiment reported evidence for a stochastic common-spectrum process affecting pulsar timing residuals in its 12.5-year dataset, which might be interpreted as the first detection of a stochastic…
Several pulsar timing arrays including NANOGrav, EPTA, PPTA, and CPTA have recently reported the observation of a stochastic background of gravitational wave spectrum in the nano-Hz frequencies. An inflationary interpretation of this…
The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed the fourth science run, S4, with significantly improved interferometer sensitivities with respect to previous runs. Using data acquired during this science run, we…
Metastable cosmic strings provide a minimal and predictive origin for the stochastic gravitational-wave background reported by Pulsar Timing Array experiments. We analyse this possibility in electroweak-like dark sectors with a single-stage…
We describe the plans for gravitational-wave observations and astrophysics that will be carried out by the LIGO Scientific Collaboration (LSC) in the next decade using data from the LIGO Observatories in the US, and sister facilities abroad…
Stochastic gravitational wave background produced by a stationary coalescing population of binary neutron stars in the Galaxy is calculated. This background is found to constitute a confusion limit within the LISA frequency band up to a…
We revisit the possibility that the stochastic common-spectrum process recently detected by the NANOGrav pulsar timing array experiment could be due to primordial gravitational waves (GWs). A na\"{i}ve extrapolation down to interferometer…
We investigate the ability of the Laser Interferometer Space Antenna (LISA) to detect a stochastic gravitational-wave background (GWB) produced by cosmic strings, and to subsequently estimate the string tension $G\mu$ in the presence of…
We briefly discuss the most prominent results and specific sources detected by gravitational-wave observatories LIGO-Virgo during first three O1-O3 runs, as well as possible astrophysical and cosmological channels of their formation. We…
The recent claim by the NANOGrav collaboration of a possible detection of an isotropic gravitational wave background stimulated a series of investigations searching for the origin of such a signal. The QCD phase transition appears as a…
The recent report of NANOGrav is gathering attention since its signal can be explained by the stochastic gravitational waves (GWs) with $\Omega_{\rm GW}\sim 10^{-9}$ at $f\sim 10^{-8}$Hz. The PBH formation scenario is one of the candidates…
We discuss cosmic domain walls described by a tension red-shifting with the expansion of the Universe. These melting domain walls emit gravitational waves with the low-frequency spectral shape $\Omega_{gw}\propto f^{2}$ corresponding to the…
We performed a Bayesian analysis of pulsar timing residuals from the NANOGrav pulsar timing array to search for a specific form of stochastic narrow-band signal produced by oscillating gravitational potential in the Galactic halo. Such…
Based on new developments in the understanding of supernovae (SNe) as gravitational-wave (GW) sources we estimate the GW background from all cosmic SNe. For a broad range of frequencies around 1 Hz, this background is crudely comparable to…
We investigate the emission of vector radiation by superconducting cosmic string loops, deriving general relations to characterize the vector radiation emission efficiency, and study its impact on the evolution of loops. Building on these…
The recent NANOGrav finding of a common-spectrum process has invited interpretations as possible evidence of a primordial stochastic gravitational-wave background (SGWB) stronger than predicted by standard inflation+LCDM. Such an SGWB would…