We compute the emission of gravitational radiation from pulsating white dwarfs. This is done by using an up-to-date stellar evolutionary code coupled with a state-of-the-art pulsational code. The emission of gravitational waves is computed for a standard 0.6M⊙ white dwarf with a liquid carbon-oxygen core and a hydrogen-rich envelope, for a massive DA white dwarf with a partially crystallized co...

We consider the possible effects of gravitational lensing by globular clusters on gravitational waves from asymmetric neutron stars in our galaxy. In the lensing of gravitational waves, the long wavelength, compared with the usual case of optical lensing, can lead to the geometrical optics approximation being invalid, in which case a wave optical solution is necessary. In general, wave optical ...

These lectures introduce some of the basic theory of cosmic microwave background (CMB) polarization with the primary aim of developing the theory of CMB polarization from inflationary gravitational waves, as well as some of the related theory of weak gravitational lensing (cosmic shear) of CMB polarization. We begin with production of polarization by Thomson scattering. We then discuss tensor-h...

O n September 14, 2015, the LIGO interferometers made the first direct measurement of gravitational waves [1]. The historic discovery came nearly 100 years after Einstein showed that his general relativity theory predicts the existence of gravitational waves and over 50 years since the first quest to observe the Universe in gravitational waves [2]. The observed event, labeled GW150914, was the ...

We develop the Polnarev’s analytic method to calculate of the polarization power spectrum of the cosmic microwave background radiation (CMB) due to relic gravitational waves. This approach complements the more precise numerical results by providing insight into the physical origins of the features in the power spectrum. We make use of the WKB approach to handle the evolution of the relic gravit...

In this contribution, we discuss the cosmological scenario where unstable domain walls are formed in the early universe and their late-time annihilation produces a significant amount of gravitational waves. After describing cosmological constraints on long-lived domain walls, we estimate the typical amplitude and frequency of gravitational waves observed today. We also review possible extension...

We calculate energy and momentum for a class of cylindrical rotating gravitational waves using Einstein and Papapetrou’s prescriptions. It is shown that the results obtained are reduced to the special case of the cylindrical gravitational waves already available in the literature. PACS: 04.20.Cv, 04.30.-w ∗Present Address: Department of Physics, Hanyang University, Seoul 133-791, KOREA 1

We analyze the high energy scattering inside gravitational backgrounds using ’t Hooft’s formalism. The scattering is equivalent to geodesic shifts accross Aichelburg-Sexl waves inside the gravitational backgrounds. We find solutions for A-S waves inside various backgrounds and analyze them.

We study tensorial perturbations (gravitational waves) in a universe with particle production (OSC). The background of gravitational waves produces a perturbation in the redshift observed from distant sources. The modes for the perturbation in the redshift(induced redshift) are calculated in a universe with particle production.