scholarly journals Further Study on the Conservation Laws of Energy-Momentum Tensor Density for a Gravitational System

2008 ◽  
Vol 48 (3) ◽  
pp. 847-856
Author(s):  
Fang-Pei Chen
Keyword(s):  
Conservation Laws ◽  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Gravitational System ◽  
Tensor Density ◽  
Conservation Laws Of Energy

scholarly journals Quasilocal conservation laws in cosmology: A first look

2020 ◽  
Vol 29 (14) ◽  
pp. 2043029
Author(s):  
Marius Oltean ◽  
Hossein Bazrafshan Moghaddam ◽  
Richard J. Epp
Keyword(s):  
General Relativity ◽  
Cosmological Constant ◽  
Conservation Laws ◽  
Perfect Fluid ◽  
Vacuum Energy ◽  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Stress Energy ◽  
Fluid Matter ◽  
Stress Energy Momentum Tensor

Quasilocal definitions of stress-energy–momentum—that is, in the form of boundary densities (in lieu of local volume densities) — have proven generally very useful in formulating and applying conservation laws in general relativity. In this Essay, we take a basic look into applying these to cosmology, specifically using the Brown–York quasilocal stress-energy–momentum tensor for matter and gravity combined. We compute this tensor and present some simple results for a flat FLRW spacetime with a perfect fluid matter source. We emphasize the importance of the vacuum energy, which is almost universally underappreciated (and usually “subtracted”), and discuss the quasilocal interpretation of the cosmological constant.

FLUIDS IN WEYL GEOMETRIES

2012 ◽  
Vol 09 (02) ◽  
pp. 1260003 ◽  
Author(s):  
L. FATIBENE ◽  
M. FRANCAVIGLIA
Keyword(s):  
Conservation Laws ◽  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Standard Relation ◽  
Number Of Particles

We shall investigate the consequences of non-trivial Weyl geometries on conservation laws of a fluid. In particular we shall obtain a set of properties which allow to obtain in this generalized setting the standard relation between conservation of the energy-momentum tensor and number of particles.

The Conservation Laws and Path-Independent Integrals for Piezo-Magnetic Media

2012 ◽  
Vol 525-526 ◽  
pp. 301-304
Author(s):  
Hai Yan Song ◽  
Jian Sheng Zhou ◽  
Zong Min Liu
Keyword(s):  
Fracture Mechanics ◽  
Conservation Laws ◽  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Important Application ◽  
Analytical Mechanics ◽  
Magnetic Media ◽  
Jacobi Integral

Path-independent integrals have important application value in dislocation, fracture mechanics and other defects theories. Motivated by concepts of Jacobi integral and cyclic integral in analytical mechanics and energy-momentum tensor in electro-magntic field, the conservation laws and path-independent integrals for piezo-magnetic media are derived in this paper.

scholarly journals On the Synergic Relationships between Special Relativity and Quantum Theories

2020 ◽  
pp. 34-43
Author(s):  
E. Comay
Keyword(s):  
Lagrangian Density ◽  
Energy Momentum Tensor ◽  
Quantum Particle ◽  
Momentum Tensor ◽  
Lagrange Equations ◽  
Quantum Theories ◽  
Hamiltonian Density ◽  
Relativistic Form ◽  
Lorentz Scalar ◽  
Conservation Laws Of Energy

The successful results of the relativistic form of a quantum field theory that is derived from aLagrangian density justify its general usage. The significance of the Euler-Lagrange equations of a quantum particle is analysed. Many advantages of this approach, like abiding by the conservation laws of energy, momentum, angular momentum, and charge are well known. The merits of this approach also include other properties that are still not well known. For example, it is shown that a quantum function of the form ψ(t, r) describes a pointlike particle. Furthermore, the Lagrangian density and the Hamiltonian density take a different relativistic form – the Lagrangian density is a Lorentz scalar, whereas the Hamiltonian density is the T00 component of the energy-momentum tensor. It is proved that inconsistencies in the electroweak theory stem from negligence of the latter point.

scholarly journals Scrambling with conservation laws

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Gong Cheng ◽  
Brian Swingle
Keyword(s):  
Field Theory ◽  
Conservation Laws ◽  
Energy Momentum Tensor ◽  
Einstein Gravity ◽  
Momentum Tensor ◽  
Late Time ◽  
Current Operator ◽  
Conformal Field ◽  
Time Value ◽  
The Impact

Abstract In this article we discuss the impact of conservation laws, specifically U(1) charge conservation and energy conservation, on scrambling dynamics, especially on the approach to the late time fully scrambled state. As a model, we consider a d + 1 dimensional (d ≥ 2) holographic conformal field theory with Einstein gravity dual. Using the holographic dictionary, we calculate out-of-time-order-correlators (OTOCs) that involve the conserved U(1) current operator or energy-momentum tensor. We show that these OTOCs approach their late time value as a power law in time, with a universal exponent $$ \frac{d}{2} $$ d 2 . We also generalize the result to compute OTOCs between general operators which have overlap with the conserved charges.

scholarly journals CONSERVATION LAWS FOR THE CLASSICAL TODA FIELD THEORIES

1993 ◽  
Vol 08 (35) ◽  
pp. 3377-3385 ◽  
Author(s):  
ERLING G. B. HOHLER ◽  
KÅRE OLAUSSEN
Keyword(s):  
Conservation Laws ◽  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Field Theories ◽  
Conformal Theory ◽  
Infinite Set ◽  
Different Origin

Some explicit calculations of the conservation laws for classical (affine) Toda field theories, and some generlizations of these models are performed. We show that there is a huge class of generalized models which have an infinite set of conservation laws, with their integrated charges being in involution. Amongst these models we find that only the Am, and [Formula: see text] Toda field theories admit such conservation laws for spin-3. The explicit calculations of spin-4 and spin-5 conservation laws in the (affine) Toda models we presented. Our perhaps most interesting finding is that there exist conservation laws in the Am, models (m≥4) which have a different origin than the exponents of the corresponding affine theory or the energy-momentum tensor of a conformal theory.

scholarly journals Homothetic congruences in general relativity

2019 ◽  
Vol 34 (01) ◽  
pp. 1950001
Author(s):  
Mohsen Fathi
Keyword(s):  
General Relativity ◽  
Black Hole ◽  
Cotangent Bundle ◽  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Electromagnetic Energy ◽  
Raychaudhuri Equation ◽  
Gravitational System ◽  
Gravitational Effects ◽  
The Common

The kinematical characteristics of distinct infalling homothetic fields are discussed by specifying the transverse subspace of their generated congruences to the energy–momentum deposit of the chosen gravitational system. This is pursued through the inclusion of the base manifold’s cotangent bundle in a generalized Raychaudhuri equation and its kinematical expressions. Exploiting an electromagnetic energy–momentum tensor as the source of non-gravitational effects, I investigate the evolution of the mentioned homothetic congruences, as they fall onto a Reissner–Nordström black hole. The results show remarkable differences to the common expectations from infalling congruences of massive particles.

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