scholarly journals From classical theory to spin 2 gravity

2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Miroslav Pardy ◽  
Keyword(s):  
Classical Theory ◽  
Einstein Equations ◽  
Principle Of Equivalence ◽  
Simple Derivation ◽  
Einstein Theory ◽  
Massless Particles ◽  
Gravity Equations ◽  
The Way

We consider here the simple derivation of the Einstein equations by Fock. Then, we approach the way from the spin 1 fields to the spin 2 fields for massive and massless particles and we derive the gravity equations from this base. In conclusion, we discuss the principle of equivalence in classical Einstein theory and in the Schwinger spin 2 gravity

scholarly journals QUANTIZING HIGHER-SPIN STRING THEORIES

1995 ◽  
Vol 10 (14) ◽  
pp. 2123-2142 ◽  
Author(s):  
H. LU ◽  
X.J. WANG ◽  
K.-W. XU ◽  
C.N. POPE ◽  
K. THIELEMANS
Keyword(s):  
String Theory ◽  
Classical Theory ◽  
Energy Momentum Tensor ◽  
Standard Form ◽  
Momentum Tensor ◽  
Minimal Models ◽  
Classical Level ◽  
Higher Spin ◽  
String Theories ◽  
The Way

In this paper, we examine the conditions under which a higher-spin string theory can be quantized. The quantizability is crucially dependent on the way in which the matter currents are realized at the classical level. In particular, we construct classical realizations for the W2,s algebra, which is generated by a primary spin-s current in addition to the energy-momentum tensor, and discuss the quantization for s≤8. From these examples we see that quantum BRST operators can exist even when there is no quantum generalization of the classical W2,s algebra. Moreover, we find that there can be several inequivalent ways of quantizing a given classical theory, leading to different BRST operators with inequivalent cohomologies. We discuss their relation to certain minimal models. We also consider the hierarchical embeddings of string theories proposed recently by Berkovits and Vafa, and show how the already known W strings provide examples of this phenomenon. Attempts to find higher-spin fermionic generalizations lead us to examine whether classical BRST operators for [Formula: see text](n odd) algebras can exist. We find that even though such fermionic algebras close up to null fields, one cannot build nilpotent BRST operators, at least of the standard form.

scholarly journals THE AVERAGING PROBLEM IN COSMOLOGY AND MACROSCOPIC GRAVITY

2008 ◽  
Vol 23 (08) ◽  
pp. 1173-1181 ◽  
Author(s):  
ROUSTAM ZALALETDINOV
Keyword(s):  
Cosmological Solution ◽  
Einstein Equations ◽  
Closed Universe ◽  
Field Equations ◽  
Correlation Tensor ◽  
Curvature Term ◽  
Averaging Problem ◽  
Gravity Equations ◽  
Spatially Homogeneous ◽  
Macroscopic Gravity

The averaging problem in cosmology and the approach of macroscopic gravity to resolve the problem is discussed. The averaged Einstein equations of macroscopic gravity are modified on cosmological scales by the macroscopic gravitational correlation tensor terms as compared with the Einstein equations of general relativity. This correlation tensor satisfies a system of structure and field equations. An exact cosmological solution to the macroscopic gravity equations for a constant macroscopic gravitational connection correlation tensor for a flat spatially homogeneous, isotropic macroscopic space-time is presented. The correlation tensor term in the macroscopic Einstein equations has been found to take the form of either a negative or positive spatial curvature term. Thus, macroscopic gravity provides a cosmological model for a flat spatially homogeneous, isotropic Universe which obeys the dynamical law for either an open or closed Universe.

Tests of the Affinity Assumption in Phantomlike Elastomer Networks

2009 ◽  
Vol 1190 ◽  
Author(s):  
Misty Davies ◽  
Adrian Lew
Keyword(s):  
Boundary Condition ◽  
Constitutive Model ◽  
Classical Theory ◽  
Local Density ◽  
Deformation Properties ◽  
Network Properties ◽  
The Way

AbstractPhantomlike elastomer simulations do not always deform globally affinely in the way that classical theory predicts. Assuming that each crosslink will deform affinely with its topological neighbors gives much better results, and creates a way to isolate crosslinks with unpredictable deformation properties. The correlation of non-affinities and network properties depends on the constitutive model and boundary condition used. We always find a correlation between local density of crosslinks and degree of non-affinity.

scholarly journals From teaching experience. VIII. Grid ornaments

2021 ◽  
Vol 7 ◽  
pp. 13-18
Author(s):  
Yu. L. Voytekhovsky ◽  
Keyword(s):  
Urban Landscape ◽  
Teaching Experience ◽  
Symmetry Groups ◽  
Simple Derivation ◽  
Actual Problem ◽  
Space Symmetry ◽  
University Course ◽  
The University ◽  
The Way

After 7 symmetry groups of borders, 17 symmetry groups of grid ornaments are the next step on the way to 230 space symmetry groups in the university course of crystallography. A simple derivation of grid ornaments is proposed, combining the search for 10 flat clusters and their translations in 5 parallelogram grids. Analysis of grid ornaments in the urban landscape (artistic mosaics, wall claddings, floorings, etc.) draws students to the actual problem of the prevalence of 230 space symmetry groups in minerals.

Did the Romans Laugh?

2012 ◽  
Vol 67 (04) ◽  
pp. 581-596
Author(s):  
Mary Beard
Keyword(s):  
Classical Theory ◽  
Political Power ◽  
Ancient Greece ◽  
Classical Antiquity ◽  
First Person ◽  
Ancient Rome ◽  
Firm Conclusion ◽  
The Past ◽  
Person Account ◽  
The Way

Laughter is one of the most difficult and intriguing historical subjects, one that defies firm conclusion or systematization. Beginning with Dion Cassius’s first-person account of laughter in the Colosseum in 192 CE, this article explores some of the heuristic challenges of writing about the laughter of the past—particularly that of classical antiquity. It attempts to undermine some of the false certainties that surround the idea of a “ classical theory of laughter” (which originated during the Renaissance) and argues that ideas about laughter in ancient Greece and Rome were much more diverse than one usually imagines. Important patterns in the discursive use of laughter in ancient Rome can nonetheless be observed. This article also examines the way laughter was used to mediate political power and autocracy in addition to how laughter operated on the boundary between animals and humans. It concludes with a reflection on the extent to which we can still share in the laughter of the Romans and under what conditions.

scholarly journals Charles Ernest Weatherburn

1976 ◽  
Vol 21 (1) ◽  
pp. 1-4 ◽  
Author(s):  
F. Gamblen
Keyword(s):  
Experimental Evidence ◽  
Classical Theory ◽  
Laws Of Nature ◽  
Principle Of Equivalence ◽  
Mathematical Difficulties

“I have received from Einstein himself a copy of his recent papers, and I shall always consider it an honour to have done so. But still I am at liberty to say that the theory does not impress me as holding the secret of the laws of nature. I feel much more disposed to trust the classical theory, modified perhaps so as to recognise the principle of equivalence. Einstein's theory is wonderful—wonderful in its complexity and in the mathematical difficulties overcome. Newton's is even more wonderful—wonderful in its simplicity and in its agreement with nearly all the experimental evidence of two and a half centuries. I cannot agree with those who would make nature more akin to the complex than to the simple.”

scholarly journals Quantum Theory of Massless Particles in Stationary Axially Symmetric Spacetimes

Entropy ◽  
2021 ◽  
Vol 23 (9) ◽  
pp. 1205
Author(s):  
Amnon Moalem ◽  
Alexander Gersten
Keyword(s):  
Wave Function ◽  
Minkowski Spacetime ◽  
Wave Functions ◽  
Axially Symmetric ◽  
Principle Of Equivalence ◽  
Massless Particles ◽  
Radial Wave ◽  
Symmetric Spacetimes ◽  
Quantum Equations ◽  
Normalization Function

Quantum equations for massless particles of any spin are considered in stationary uncharged axially symmetric spacetimes. It is demonstrated that up to a normalization function, the angular wave function does not depend on the metric and practically is the same as in the Minkowskian case. The radial wave functions satisfy second order nonhomogeneous differential equations with three nonhomogeneous terms, which depend in a unique way on time and space curvatures. In agreement with the principle of equivalence, these terms vanish locally, and the radial equations reduce to the same homogeneous equations as in Minkowski spacetime.

PROPERTIES AND DRAWING OF THE SO‐CALLED DAR ZARROUK CURVES

Geophysics ◽  
1963 ◽  
Vol 28 (1) ◽  
pp. 99-110 ◽  
Author(s):  
Ernesto Orellana
Keyword(s):  
Physical Significance ◽  
Principle Of Equivalence ◽  
Depth Of Penetration ◽  
Different Types ◽  
Electrical Prospecting ◽  
The Way

The physical significance of the so‐called Dar Zarrouk curves (Maillet) is clarified and some new conclusions are drawn. A method is described for the quick and accurate construction of these curves based on the properties cited. The author illustrates the way to use them in solving different types of problems related to electrical prospecting, such as the determination of the limits of validity of the principle of equivalence, the depth of penetration, the possibility of differentiating between similar formations, etc. Five practical examples are discussed, and a template for use in the construction of Dar Zarrouk curves is included.

Self-sacrifice for in-group's history: A diachronic perspective

2018 ◽  
Vol 41 ◽  
Author(s):  
Maria Babińska ◽  
Michal Bilewicz
Keyword(s):  
Clinical Psychology ◽  
Historical Events ◽  
Emotional Events ◽  
Reciprocal Process ◽  
The Way

AbstractThe problem of extended fusion and identification can be approached from a diachronic perspective. Based on our own research, as well as findings from the fields of social, political, and clinical psychology, we argue that the way contemporary emotional events shape local fusion is similar to the way in which historical experiences shape extended fusion. We propose a reciprocal process in which historical events shape contemporary identities, whereas contemporary identities shape interpretations of past traumas.

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