The signal of the gravitational wave background and the angular correlation of its energy density

Regular high-precision timing of the binary pulsars J0613−0200, J1012+5307, J1022+1001, J1640+2224, J1643−1224, J1713+0747, J2145−0750 and the pulsar B1937+21 has been conducted at the Kalyazin (Russia) radio telescope RT-64 at 0.6 GHz over more than 6 years. Several of the pulsars monitored have been found to be good probes for gravitational wave background (GWB) tests, while others, having a shorter orbital period, can be used for establishing a dynamical binary pulsar timescale. Upper limits for the GWB energy density were estimated.

Download Full-text

THE QUANTUM CREATION OF THE UNIVERSE CAN BE OBSERVATIONALLY VERIFIED

Modern Physics Letters A ◽

10.1142/s0217732387000781 ◽

1987 ◽

Vol 02 (09) ◽

pp. 631-634 ◽

Cited By ~ 3

Author(s):

L. P. GRISHCHUK

Keyword(s):

Energy Density ◽

Gravitational Wave ◽

Gravitational Wave Background ◽

The Universe

It is shown that the properly formulated notion of the quantum birth of the universe can be observationally confirmed or rejected. The idea is that the energy density and spectrum of the relic gravitational wave background is determined by a wavefunction of the universe not only in classically allowed but also in classically forbidden regimes.

Download Full-text

Intensity and anisotropies of the stochastic gravitational wave background from merging compact binaries in galaxies

Journal of Cosmology and Astroparticle Physics ◽

10.1088/1475-7516/2021/11/032 ◽

2021 ◽

Vol 2021 (11) ◽

pp. 032

Author(s):

Giulia Capurri ◽

Andrea Lapi ◽

Carlo Baccigalupi ◽

Lumen Boco ◽

Giulio Scelfo ◽

...

Keyword(s):

Energy Density ◽

Power Spectrum ◽

Gravitational Wave ◽

Power Spectra ◽

Redshift Distribution ◽

Full Generality ◽

Isotropic Energy ◽

Angular Power Spectrum ◽

Compact Binaries ◽

Gravitational Wave Background

Abstract We investigate the isotropic and anisotropic components of the Stochastic Gravitational Wave Background (SGWB) originated from unresolved merging compact binaries in galaxies. We base our analysis on an empirical approach to galactic astrophysics that allows to follow the evolution of individual systems. We then characterize the energy density of the SGWB as a tracer of the total matter density, in order to compute the angular power spectrum of anisotropies with the Cosmic Linear Anisotropy Solving System (CLASS) public code in full generality. We obtain predictions for the isotropic energy density and for the angular power spectrum of the SGWB anisotropies, and study the prospect for their observations with advanced Laser Interferometer Gravitational-Wave and Virgo Observatories and with the Einstein Telescope. We identify the contributions coming from different type of sources (binary black holes, binary neutron stars and black hole-neutron star) and from different redshifts. We examine in detail the spectral shape of the energy density for all types of sources, comparing the results for the two detectors. We find that the power spectrum of the SGWB anisotropies behaves like a power law on large angular scales and drops at small scales: we explain this behavior in terms of the redshift distribution of sources that contribute most to the signal, and of the sensitivities of the two detectors. Finally, we simulate a high resolution full sky map of the SGWB starting from the power spectra obtained with CLASS and including Poisson statistics and clustering properties.

Download Full-text