Conveners
Gravity and gravitational waves
- Rohana Wijewardhana
Gravity and gravitational waves
- Shinji Tsujikawa (Tokyo University of Science)
We investigate the cosmological background evolution and perturbations in a
general class of spatially covariant theories of gravity, which propagates two tensor modes and
one scalar mode. We show that the structure of the theory is preserved under the disformal
transformation. We also evaluate the primordial spectra for both the gravitational waves and
the curvature perturbation, which...
The recent detections of gravitational waves from coalescing binary black holes by the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) suggest that a stochastic gravitational wave background may be detectable by advanced detectors running at their design sensitivity. Looking at results from searches for both isotropic and anisotropic stochastic backgrounds in Advanced...
The gravitational wave signal GW150914, recently detected by LIGO and Virgo collaborations, is used to place a bound on the scale of quantum fuzziness of non-commutative space-time. We show that the leading non-commutative correction to the phase of the gravitational waves produced by a binary system appears at the 2nd order of the post-Newtonian expansion. This correction is proportional to...
Ever since the observation of Bekenstein that not only black hole mechanics can be given the form of the laws of thermodynamics, with area of horizon playing the role of
entropy, the surface gravity of temperature and the mass of the black hole as energy, the study of black hole thermodynamics has been a very active area of research due to fundamental problems posed by such a connection....
The close connection between horizons (black hole event horizon, Rindler, de Sitter) and thermodynamics that has already been found can be extended here to a cosmological model, providing a new insight into the cosmological constant problem. The emergent nature of the field equations is interpreted as entropy balance condition of the spacetime. We describe various facets of the emergent...
We discuss the role of consistency with causality and quantum mechanics in determining the properties of gravity. We begin by constructing theories of interacting massless spin 2 particles -- gravitons. One theory involves coupling the graviton with the lowest number of derivatives to matter, the other theories involve coupling the graviton with higher derivatives to matter. The first theory...
Cai and Kim [JHEP02(2005)050] proposed an interpretation of black hole thermodynamics for an expanding universe in Einstein, Gauss-Bonnet and Lovelock gravity. There have been since then numerous applications and interpretions of the entanglement entropy to the universe. In this talk, the recent progress in this direction will be critically reviewed and revisited from the view point of current...
First, I describe the motivation of this work and then introduce a simple toy model which is useful to understand the essential point of our theorem.
Next, I show that the following two sets of equations are equivalent if the gauge fixing is complete:
One is the Euler-Lagrange equations derived from the original action supplemented with the gauge-fixing conditions, and the other is the...
Time dependent brane solutions of supergravity have been
of particular importance in the advances of gravity theory.
We review the current status of these "dynamical" brane solutions
in higher-dimensional supergravity theories and discuss primarily
the gravitational aspects of p-branes and their relatives in various
dimensions. We also comment the D-brane and M-brane solutions
in ten and...
