Related papers: Updated Constraints and Forecasts on Primordial Te…
Primordial gravitational waves could be non-Gaussian, just like primordial scalar perturbations. Although the tensor two-point function has thus-far remained elusive, the three-point function could, in principle, be large enough to be…
The detection of gravitational waves (GW) by the LIGO and Virgo collaborations offers a whole new range of possible tests and opens up a new window which may shed light on the nature of dark energy and dark matter. In the present work we…
Standard sirens are the gravitational wave (GW) analog of the astronomical standard candles, and can provide powerful information about the dynamics of the Universe. In this work, we simulate a catalog with 1000 standard siren events from…
We update constraints on the amplitude of the primordial trispectrum, using the final Planck mission temperature and polarization data. In the squeezed limit, a cosmological local trispectrum would be observed as a spatial modulation of…
We probe ultra-low-frequency gravitational waves (GWs) with statistics of spin-down rates of milli-second pulsars (MSPs) by a method proposed in our prevous work (Yonemaru et al. 2016). The considered frequency range is $10^{-12}{\rm Hz}…
The prospect of detecting relic gravitational waves (RGWs), through their imprint in the cosmic microwave background radiation, provides an excellent opportunity to study the very early Universe. In simplest viable theoretical models the…
We analyse the Planck full-mission cosmic microwave background (CMB) temperature and E-mode polarization maps to obtain constraints on primordial non-Gaussianity (NG). We compare estimates obtained from separable template-fitting, binned,…
In this paper, we investigate scalar-induced gravitational waves (GWs) generated in the post-inflationary universe to infer new limits on warm inflation. We specifically examine the evolution of primordial GWs by scalar perturbations…
In this work, we use the simulated gravitational wave (GW) standard siren data from the future observation of the Einstein Telescope (ET) to constrain various dark energy cosmological models, including the $\Lambda$CDM, $w$CDM, CPL,…
In the last decade Planck PR4 data together with ground-based experimental data such as, BK18, BAO and CMB lensing, tightened constraint of the tensor to scalar ratio, starting form $r < 0.14$ to $r < 0.032$, while the spectral index lies…
We present new astrometric constraints on the stochastic gravitational wave background and construct the first astrometric Hellings-Downs curve using quasar proper motions. From quadrupolar vector spherical harmonic fits to the Gaia proper…
We update the constraints on the cosmological parameters by adopting the Planck data released in 2015 and Baryon Acoustic Oscillation (BAO) measurements including the new DR14 quasar sample measurement at redshift $z=1.52$, and we conclude…
In modified gravity theories, the gravitational waves propagation are presented in nonstandard ways. We consider a friction term different from GR and constrain the modified gravitational waves propagation from observations. The modified…
We propose a new strategy to probe non-tensorial polarizations in the stochastic gravitational-wave (GW) background. Averaging over polarization angles, we find that three-point correlations of the GW signal vanish for tensor and vector…
We explore the thermal light sterile neutrino situation from cosmological perspective in the $\Lambda \textrm{CDM} + r_{0.05} + N_{\textrm{eff}} + m^{\textrm{eff}}_{\textrm{s}}$ model using combinations of latest data sets available. Here,…
We demonstrate how to obtain optimal constraints on a primordial gravitational wave component in lensed Cosmic Microwave Background (CMB) data under ideal conditions. We first derive an estimator of the tensor-to-scalar ratio, $r$, by using…
In the measurements of cosmic microwave background polarizations, three frequency channels are necessary for discriminating the primordial B-modes from the polarized dust and the synchrotron emission. We carry out an optimistic estimate on…
We present the implications for cosmic inflation of the Planck measurements of the cosmic microwave background (CMB) anisotropies in both temperature and polarization based on the full Planck survey. The Planck full mission temperature data…
Thompson scattering of cosmic microwave background (CMB) photons off of free electrons during the reionization epoch induces a correlation between the distribution of galaxies and the polarization pattern of the CMB, the magnitude of which…
The detection of a stochastic signal by recent pulsar timing array (PTA) collaborations, including NANOGrav, PPTA, EPTA+InPTA, CPTA and MPTA, has opened a new window to explore gravitational waves (GWs) at nanohertz frequencies. Motivated…