相关论文: On the propagation of gravitational waves in a $\L…
In this talk I review how a non-zero cosmological constant $\Lambda$ affects the propagation of gravitational waves and their detection in pulsar timing arrays (PTA). If $\Lambda\neq 0$ it turns out that waves are anharmonic in cosmological…
We have considered the propagation of gravitational waves (GW) in de Sitter space time and how a non-zero value of the cosmological constant might affect their detection in pulsar timing arrays (PTA). If {\Lambda} is different from zero…
Recent research show that the cosmological components of the Universe should influence on the propagation of Gravitational Waves (GWs) and even it has been proposed a new way to measure the cosmological constant using Pulsar Timing Arrays…
Some time ago it was pointed out that the presence of cosmological components could affect the propagation of gravitational waves (GW) beyond the usual cosmological redshift and that such effects might be observable in pulsar timing arrays.…
We study the effect of a cosmological constant $\Lambda$ on the propagation and detection of gravitational waves. To this purpose we investigate the linearised Einstein's equations with terms up to linear order in $\Lambda$ in a de Sitter…
Massive black holes are key components of the assembly and evolution of cosmic structures and a number of surveys are currently on-going or planned to probe the demographics of these objects and to gain insight into the relevant physical…
The expansion of the Universe is accelerating which can be interpreted as due to the cosmological constant $\Lambda$. In this study, we investigate the behavior of gravitational waves in the presence of a cosmological constant in the early…
Supermassive black hole binaries source gravitational waves measured by Pulsar Timing Arrays. The frequency spectrum of this stochastic background is predicted more precisely than its amplitude. We argue that Dark Matter friction can…
Space-borne gravitational wave detectors, such as the proposed Laser Interferometer Space Antenna, are expected to observe black hole coalescences to high redshift and with large signal-to-noise ratios, rendering their gravitational waves…
Gravitational waves provide a new probe of the Universe which can reveal a number of cosmological and astrophysical phenomena that cannot be observed by electromagnetic waves. Different frequencies of gravitational waves are detected by…
We have begun an exciting era for gravitational wave detection, as several world-leading experiments are breaching the threshold of anticipated signal strengths. Pulsar timing arrays (PTAs) are pan-Galactic gravitational wave detectors that…
We derive the effects of a non-zero cosmological constant $\Lambda$ on gravitational wave propagation in the linearized approximation of general relativity. In this approximation we consider the situation where the metric can be written as…
If the cosmological QCD phase transition is strongly first order and lasts sufficiently long, it generates a background of gravitational waves which may be detected via pulsar timing experiments. We estimate the amplitude and the spectral…
One of the open questions of modern cosmology is the nature and properties of the Dark Matter halo and its substructures. In this work we study the gravitational effect of dark matter substructures on pulsar timing observations. Since…
Gravitational waves are expected to be radiated by supermassive black hole binaries formed during galaxy mergers. A stochastic superposition of gravitational waves from all such binary systems will modulate the arrival times of pulses from…
We examine gravitational wave memory in the case where sources and detector are in a $\Lambda$CDM cosmology. We consider the case where the universe can be highly inhomogeneous, but the gravitatational radiation is treated in the short…
Consideration of vacuum polarization in quantum electrodynamics may affect the momentum dispersion relation for photons for a non-trivial background, due to appearance of curvature dependent terms in the effective action. We investigate the…
Pulsar timing arrays act to detect gravitational waves by observing the small, correlated effect the waves have on pulse arrival times at Earth. This effect has conventionally been evaluated assuming the gravitational wave phasefronts are…
Massive black holes are key ingredients of the assembly and evolution of cosmic structures. Pulsar Timing Arrays (PTAs) currently provide the only means to observe gravitational radiation from massive black hole binary systems with masses…
Pulsar timing uses the highly stable pulsar spin period to investigate many astrophysical topics. In particular, pulsar timing arrays make use of a set of extremely well-timed pulsars and their time correlations as a challenging detector of…