TS-LIKE GRAVITATIONAL WAVES IN 4D EINSTEIN GRAVITY

2010 ◽  
Vol 25 (07) ◽  
pp. 557-566
Author(s):  
YI-HUAN WEI
Keyword(s):  
Gravitational Wave ◽  
Gravitational Waves ◽  
Coordinate Transformation ◽  
Wave Solution ◽  
Einstein Gravity ◽  
Gauge Potential ◽  
Wave Solutions

We propose TS-like class of gravitational wave solutions in 4D Einstein gravity. TS1-like gravitational wave solution is analyzed in detail. On the axis, the gauge potential changes from a finite value to zero at t = τ. The spacetime on the axis approaches the flat one as t → ∞. It is found that by an appropriate parameter substitution and coordinate transformation TS-like gravitational wave solutions in 4D Einstein gravity may be obtained from TS solutions.

scholarly journals Spherical gravitational waves and quasi-spherical waves scattered from black string in massive gravity

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Hongsheng Zhang ◽  
Yang Huang
Keyword(s):  
General Relativity ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Wave Solution ◽  
Massive Gravity ◽  
Back Reaction ◽  
Birkhoff Theorem ◽  
Spherical Waves ◽  
Linear Perturbations ◽  
Singular Reference

Abstract Spherical gravitational wave is strictly forbidden in vacuum space in frame of general relativity by the Birkhoff theorem. We prove that spherical gravitational waves do exist in non-linear massive gravity, and find the exact solution with a special singular reference metric. Further more, we find exact gravitational wave solution with a singular string by meticulous studies of familiar equation, in which the horizon becomes non-compact. We analyze the properties of the congruence of graviton rays of these wave solution. We clarify subtle points of dispersion relation, velocity and mass of graviton in massive gravity with linear perturbations. We find that the graviton ray can be null in massive gravity by considering full back reaction of the massive gravitational waves to the metric. We demonstrate that massive gravity has deep and fundamental discrepancy from general relativity, for whatever a tiny mass of the graviton.

scholarly journals Cylindrical Gravitational Wave: Source and Resonance

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1425
Author(s):  
Yu-Zhu Chen ◽  
Shi-Lin Li ◽  
Yu-Jie Chen ◽  
Wu-Sheng Dai
Keyword(s):  
General Solution ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Field Approximation ◽  
Weak Field ◽  
Cylindrical Symmetry ◽  
Time Averaging ◽  
Wave Source ◽  
Wave Solutions ◽  
Special Cases

Gravitational waves are regarded as linear waves in the weak field approximation, which ignores the spacetime singularity. In this paper, we analyze singularities in exact gravitational wave solutions. We provide an exact general solution of the gravitational wave with cylindrical symmetry. The general solution includes some known cylindrical wave solutions as special cases. We show that there are two kinds of singularities in the cylindrical gravitational wave solution. The first kind of singularity corresponds to a singular source. The second kind of singularity corresponds to a resonance between different gravitational waves. When two gravitational waves coexist, the interference term in the source may vanish in the sense of time averaging.

THE EFFECT OF POLARIZATION OF COLLIDING PLANE GRAVITATIONAL WAVES ON FOCUSING SINGULARITIES

1991 ◽  
Vol 06 (13) ◽  
pp. 2273-2288 ◽  
Author(s):  
ANZHONG WANG
Keyword(s):  
Gravitational Wave ◽  
Gravitational Waves ◽  
Polarization Plane ◽  
Plane Gravitational Wave ◽  
Wave Solutions ◽  
Plane Gravitational Waves

A five-parameter class of colliding plane gravitational wave solutions is obtained by using the soliton technique of Belinsky and Zakharov, which includes most of the important known solutions. A four-parameter subclass of the solutions can be considered as a noncollinear generalization of the famous Szekeres family of colliding collinear polarization plane gravitational wave solutions. The effect of polarization of colliding plane gravitational waves on the formation and nature of singularities is, in turn, investigated.

APPROXIMATE GRAVITATIONAL WAVES VIA DEFORMATIONS OF EMBEDDINGS

2009 ◽  
Vol 24 (08n09) ◽  
pp. 1465-1472 ◽  
Author(s):  
RICHARD KERNER ◽  
SALVATORE VITALE
Keyword(s):  
Gravitational Wave ◽  
Gravitational Waves ◽  
Einstein Space ◽  
Einstein Equations ◽  
Euclidean Spaces ◽  
Infinitesimal Deformation ◽  
Wave Solutions ◽  
Einstein Spaces ◽  
Derivatives Of

Many Einstein spaces can be embedded globally in pseudo-Euclidean spaces of dimension N > 4. The geometrical quantities characterizing the embedded manifold can be expressed by means of derivatives of the embedding functions zA (xµ), A, B, = 1, 2, …N, µ, ν, …= 0, 1, 2, 3. An infinitesimal deformation of embedding can be expanded into a series [Formula: see text], giving rise to a similar expansion of geometrical quantities of the embedded Einstein space, and the Einstein equations in vacuo, too. We show how gravitational wave solutions appear naturally in this context.

Problems on the Gravitational Wave and the Repulsive Gravitation

2016 ◽  
pp. 4422-4429
Author(s):  
C. Y. Lo
Keyword(s):  
Black Holes ◽  
Gravitational Wave ◽  
Einstein Equation ◽  
Wave Solution ◽  
Dynamic Solution ◽  
Pure Mathematics ◽  
Non Linear

It is exciting that the gravitational wave has been confirmed, according to the announcement of LIGO. This would be the time to fix the Einstein equation for the gravitational wave and the nonexistence of the dynamic solution. As a first step, theorists should improve their pure mathematics on non-linear mathematics and related physical considerations beyond Einstein. Then, it is time to rectify the Einstein equation that has no gravitational wave solution which Einstein has recognized, and no dynamic solution that Einstein failed to see. A problem is that physicists in LIGO did not know their shortcomings. Also, in view of the far distance of the sources, it is very questionable that the physicists can determine they are from black holes. Moreover, since the repulsive gravitation can also generate a gravitational wave, the problem of gravitational wave is actually far more complicated than we have known. A useful feature of the gravitational wave based on repulsive gravitation is that it can be easily generated on earth. Thus this can be a new tool for communication because it can penetrate any medium.

scholarly journals Gravitational waves from mountains in newly born millisecond magnetars

2021 ◽  
Vol 502 (4) ◽  
pp. 4680-4688
Author(s):  
Ankan Sur ◽  
Brynmor Haskell
Keyword(s):  
Gravitational Wave ◽  
Gravitational Waves ◽  
Massive Star ◽  
Gamma Ray ◽  
Dipole Radiation ◽  
X Ray ◽  
Binary Neutron Star ◽  
Spin Period ◽  
Lower Maximum ◽  
Wave Emission

ABSTRACT In this paper, we study the spin-evolution and gravitational-wave luminosity of a newly born millisecond magnetar, formed either after the collapse of a massive star or after the merger of two neutron stars. In both cases, we consider the effect of fallback accretion; and consider the evolution of the system due to the different torques acting on the star, namely the spin-up torque due to accretion and spin-down torques due to magnetic dipole radiation, neutrino emission, and gravitational-wave emission linked to the formation of a ‘mountain’ on the accretion poles. Initially, the spin period is mostly affected by the dipole radiation, but at later times, accretion spin the star up rapidly. We find that a magnetar formed after the collapse of a massive star can accrete up to 1 M⊙, and survive on the order of 50 s before collapsing to a black hole. The gravitational-wave strain, for an object located at 1 Mpc, is hc ∼ 10−23 at kHz frequencies, making this a potential target for next-generation ground-based detectors. A magnetar formed after a binary neutron star merger, on the other hand, accretes at the most 0.2 M⊙ and emits gravitational waves with a lower maximum strain of the order of hc ∼ 10−24, but also survives for much longer times, and may possibly be associated with the X-ray plateau observed in the light curve of a number of short gamma-ray burst.

scholarly journals Single peaked traveling wave solutions to a generalized μ-Novikov Equation

2020 ◽  
Vol 10 (1) ◽  
pp. 66-75
Author(s):  
Byungsoo Moon
Keyword(s):  
Linear Combination ◽  
Traveling Wave ◽  
Wave Solution ◽  
Traveling Wave Solutions ◽  
Traveling Wave Solution ◽  
Wave Solutions ◽  
Quadratic Nonlinearities ◽  
Novikov Equation

Abstract In this paper, we study the existence of peaked traveling wave solution of the generalized μ-Novikov equation with nonlocal cubic and quadratic nonlinearities. The equation is a μ-version of a linear combination of the Novikov equation and Camassa-Hom equation. It is found that the equation admits single peaked traveling wave solutions.

scholarly journals Gravitational wave–gauge field dynamics

2017 ◽  
Vol 26 (12) ◽  
pp. 1742005 ◽  
Author(s):  
R. R. Caldwell ◽  
C. Devulder ◽  
N. A. Maksimova
Keyword(s):  
Quantum Gravity ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Gauge Field ◽  
Linear Combination ◽  
Effective Mass ◽  
Normal Modes ◽  
New Approaches ◽  
Insight Into

The dynamics of a gravitational wave propagating through a cosmic gauge field are dramatically different than in vacuum. We show that a gravitational wave acquires an effective mass, is birefringent, and its normal modes are a linear combination of gravitational waves and gauge field excitations, leading to the phenomenon of gravitational wave–gauge field oscillations. These surprising results provide an insight into gravitational phenomena and may suggest new approaches to a theory of quantum gravity.

Tidal deformation of quantum black holes

2021 ◽  
pp. 2142011
Author(s):  
Ram Brustein ◽  
Yotam Sherf
Keyword(s):  
Black Holes ◽  
Perturbation Theory ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Excited Level ◽  
Love Number ◽  
Standard Time ◽  
Love Numbers ◽  
Classical Black Holes ◽  
Quantum Perturbation Theory

The response of a gravitating object to an external tidal field is encoded in its Love numbers, which identically vanish for classical black holes (BHs). Here we show, using standard time-independent quantum perturbation theory, that for a quantum BH, generically, the Love numbers are nonvanishing and negative. We calculate the quadrupolar electric quantum Love number of slowly rotating BHs and show that it depends most strongly on the first excited level of the quantum BH. Finally, we discuss the detectability of the quadrupolar quantum Love number in future precision gravitational-wave observations and show that, under favourable circumstances, its magnitude is large enough to imprint an observable signature on the gravitational waves emitted during the inspiral. Phase of two moderately spinning BHs.

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