相关论文: Sensitivity to a Frequency-Dependent Circular Pola…
Fast radio bursts (FRBs) are extra-galactic sources with unknown physical mechanisms. They emit millisecond-duration radio pulses with isotropic equivalent energy of $10^{36}\sim10^{41}$ ergs. This corresponds to a brightness temperature of…
The Stokes V parameter characterizes asymmetry of amplitudes between right- and left-handed waves, and non-vanishing value of the V parameter yields a circularly polarized signal. Cosmologically, V parameter may be a direct probe for parity…
Gravitational waves at kilohertz and higher frequencies offer a unique probe of the early Universe at temperatures well beyond the reach of the cosmic microwave background, corresponding to energy scales $\gtrsim 10^9$GeV. Existing detector…
Future missions of gravitational-wave astronomy will be operated by space-based interferometers, covering very wide range of frequency. Search for stochastic gravitational-wave backgrounds (GWBs) is one of the main targets for such…
We study the sensitivity of a pair of Einstein Telescopes (ET) (hypothetically located at the two sites currently under consideration for ET) to the anisotropies of the Stochastic Gravitational Wave Background (SGWB). We focus on the $\ell…
The stochastic gravitational-wave background is imprinted on the times of arrival of radio pulses from millisecond pulsars. Traditional pulsar timing analyses fit a timing model to each pulsar and search the residuals of the fit for a…
Circularly polarized gravitational wave backgrounds are predicted in many well-motivated models of inflation and phase transitions involving spontaneous parity violation. In this work, we investigate the detection of such parity-violating…
Circular polarization in the cosmic microwave background (CMB) offers a promising probe of the parity-violating physics of the early universe. In this paper, we propose a novel method to constrain the primordial circular polarization of…
Pulsar timing arrays (PTAs), aimed at detecting gravitational waves (GWs) in the $1\sim 100$ nHz range, have recently made significant strides. Compelling evidence has emerged for a common spectrum signal spatially correlated among pulsars,…
While general relativity predicts only two tensor modes for gravitational wave polarization, general metric theories of gravity allows up to four additional modes, including two vector and two scalar modes. Observing the polarization modes…
Polarization leakage of foreground synchrotron emission is a critical issue in HI intensity mapping experiments. While the sought-after HI emission is unpolarized, polarized foregrounds such as Galactic and extragalactic synchrotron…
A new detection method for gravitational waves (GWs) with ultra-low frequencies ($f_{\rm GW} \lesssim 10^{-10}~{\rm Hz}$), which is much lower than the range of pulsar timing arrays (PTAs), was proposed in Yonemaru et al. (2016). This…
At nanohertz frequencies gravitational waves (GWs) cause variations in time-of-arrival of pulsar signals potentially measurable via precision timing observations. Here we compute very-low-frequency GW sensitivity constrained by…
BICEP2 has reported the detection of a degree-scale B-mode polarization pattern in the Cosmic Microwave Background (CMB) and has interpreted the measurement as evidence for primordial gravitational waves. Motivated by the profound…
A method is suggested to explore the gravitational wave background (GWB) in the frequency range from $10^{-12}$ to \hbox{$10^{-8}$ Hz}. That method is based on the precise measurements of pulsars' rotational parameters: the influence of the…
The geometric optics approximation traditionally used to study the propagation of gravitational waves on a curved background, breaks down in the vicinity of compact and extended astrophysical objects, where wave-like effects like diffusion…
We have analyzed the polarization properties of pulsars at an observing frequency of 4.9 GHz. Together with low frequency data, we are able to trace polarization profiles over more than three octaves into an interesting frequency regime. At…
To determine whether particular sources of gravitational radiation will be detectable by a specific gravitational wave detector, it is necessary to know the sensitivity limits of the instrument. These instrumental sensitivities are often…
In a general metric theory of gravitation in four dimensions, six polarizations of a gravitational wave are allowed: two scalar and two vector modes, in addition to two tensor modes in general relativity. Such additional polarization modes…
We search for isotropic stochastic gravitational-wave background (SGWB) in the International Pulsar Timing Array second data release. By modeling the SGWB as a power-law, we find very strong Bayesian evidence for a common-spectrum process,…