scholarly journals Space-Time Defects and Group Momentum Space

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Michele Arzano ◽  
Tomasz Trześniewski
Keyword(s):  
Minkowski Space ◽  
Lorentz Group ◽  
Momentum Space ◽  
Abelian Subgroup ◽  
Space Time ◽  
Noncommutative Space ◽  
De Sitter ◽  
Maximal Abelian Subgroup ◽  
Dimensional Minkowski Space ◽  
Poincaré Algebra

We study massive and massless conical defects in Minkowski and de Sitter spaces in various space-time dimensions. The energy momentum of a defect, considered as an (extended) relativistic object, is completely characterized by the holonomy of the connection associated with its space-time metric. The possible holonomies are given by Lorentz group elements, which are rotations and null rotations for massive and massless defects, respectively. In particular, if we fix the direction of propagation of a massless defect in n+1-dimensional Minkowski space, then its space of holonomies is a maximal Abelian subgroup of the AN(n-1) group, which corresponds to the well known momentum space associated with the n-dimensional κ-Minkowski noncommutative space-time and κ-deformed Poincaré algebra. We also conjecture that massless defects in n-dimensional de Sitter space can be analogously characterized by holonomies belonging to the same subgroup. This shows how group-valued momenta related to four-dimensional deformations of relativistic symmetries can arise in the description of motion of space-time defects.

scholarly journals Elastic shocks in relativistic rigid rods and balls

2019 ◽  
Vol 475 (2225) ◽  
pp. 20180858 ◽  
Author(s):  
João L. Costa ◽  
José Natário
Keyword(s):  
Free Boundary ◽  
Minkowski Space ◽  
Initial Conditions ◽  
Equations Of Motion ◽  
Time Derivative ◽  
Space Time ◽  
Spherically Symmetric ◽  
Soft Phase ◽  
Minkowski Space Time ◽  
Dimensional Minkowski Space

We study the free boundary problem for the ‘hard phase’ material introduced by Christodoulou in (Christodoulou 1995 Arch. Ration. Mech. Anal. 130 , 343–400), both for rods in (1 + 1)-dimensional Minkowski space–time and for spherically symmetric balls in (3 + 1)-dimensional Minkowski space–time. Unlike Christodoulou, we do not consider a ‘soft phase’, and so we regard this material as an elastic medium, capable of both compression and stretching. We prove that shocks must be null hypersurfaces, and derive the conditions to be satisfied at a free boundary. We solve the equations of motion of the rods explicitly, and we prove existence of solutions to the equations of motion of the spherically symmetric balls for an arbitrarily long (but finite) time, given initial conditions sufficiently close to those for the relaxed ball at rest. In both cases we find that the solutions contain shocks if and only if the pressure or its time derivative do not vanish at the free boundary initially. These shocks interact with the free boundary, causing it to lose regularity.

scholarly journals DOUBLY SPECIAL RELATIVITY VERSUS κ-DEFORMATION OF RELATIVISTIC KINEMATICS

2003 ◽  
Vol 18 (01) ◽  
pp. 7-18 ◽  
Author(s):  
JERZY LUKIERSKI ◽  
ANATOL NOWICKI
Keyword(s):  
Special Relativity ◽  
Minkowski Space ◽  
Noncommutative Space ◽  
Relativistic Kinematics ◽  
Large Classes ◽  
Doubly Special Relativity ◽  
Deformed Minkowski Space ◽  
Composition Law ◽  
Poincaré Algebra ◽  
The One

We argue that the so-called doubly special relativity (DSR), recently proposed by Amelino-Camelia et al.1,2 with deformed boost transformations identical with the formulae for κ-deformed kinematics in bicrossproduct basis is classical special relativity in nonlinear disguise. The choice of symmetric composition law for deformed four-momenta as advocated in Refs. 1 and 2 implies that DSR is obtained by considering the nonlinear four-momenta basis of classical Poincaré algebra and it does not lead to noncommutative space–time. We also show how to construct two large classes of doubly special relativity theories — generalizing the choice in Refs. 1 and 2 and the one presented by Magueijo and Smolin.3 The older version of deformed relativistic kinematics, differing essentially from classical theory in the coalgebra sector and leading to noncommutative κ-deformed Minkowski space is provided by quantum κ-deformation of Poincaré symmetries.

scholarly journals NEGATIVE NORM STATES IN DE SITTER SPACE AND QFT WITHOUT RENORMALIZATION PROCEDURE

2002 ◽  
Vol 11 (06) ◽  
pp. 509-518 ◽  
Author(s):  
MOHAMMAD VAHID TAKOOK
Keyword(s):  
Minkowski Space ◽  
De Sitter Space ◽  
Infrared Divergence ◽  
Space Time ◽  
Ultraviolet Divergence ◽  
De Sitter ◽  
Physical Content ◽  
Negative Norm ◽  
Minkowski Space Time ◽  
Loop Approximation

In recent papers,1,2 it has been shown that the presence of negative norm states or negative frequency solutions are indispensable for a fully covariant quantization of the minimally coupled scalar field in de Sitter space. Their presence, while leaving unchanged the physical content of the theory, offers the advantage of eliminating any ultraviolet divergence in the vacuum energy2 and infrared divergence in the two point function.3 We attempt here to extend this method to the interacting quantum field in Minkowski space-time. As an illustration of the procedure, we consider the λϕ4 theory in Minkowski space-time. The mathematical consequences of this method is the disappearance of the ultraviolet divergence to the one-loop approximation. This means, the effect of these auxiliary negative norm states is to allow an automatic renormalization of the theory in this approximation.

A STRING MODEL FOR D-DIMENSIONAL DE SITTER SPACE–TIME AND EQUATIONS OF MOTION

2005 ◽  
Vol 20 (26) ◽  
pp. 6065-6081
Author(s):  
PAUL BRACKEN
Keyword(s):  
Evolution Equations ◽  
Gordon Equation ◽  
Equations Of Motion ◽  
String Model ◽  
De Sitter Space ◽  
Space Time ◽  
System Of Equations ◽  
De Sitter ◽  
Minkowski Space Time ◽  
Dimensional Minkowski Space

De Sitter space–time is considered to be represented by a D-dimensional hyperboloid embedded in (D+1)-dimensional Minkowski space–time. The string equation is derived from a string action which contains a Lagrange multiplier to restrict coordinates to de Sitter space–time. The string system of equations is equivalent to a type of generalized sinh–Gordon equation. The evolution equations for all the variables including the coordinates and their derivatives are obtained for D=2,3 and 4.

scholarly journals THERMAL QUANTUM FIELDS WITHOUT CUT-OFFS IN 1+1 SPACE-TIME DIMENSIONS

2005 ◽  
Vol 17 (02) ◽  
pp. 113-173 ◽  
Author(s):  
CHRISTIAN GÉRARD ◽  
CHRISTIAN D. JÄKEL
Keyword(s):  
Minkowski Space ◽  
Space Time ◽  
Positive Temperature ◽  
Prior Work ◽  
Quantum Fields ◽  
Neutral Scalar ◽  
Dimensional Minkowski Space

We construct interacting quantum fields in 1+1 dimensional Minkowski space, representing neutral scalar bosons at positive temperature. Our work is based on prior work by Klein and Landau and Høegh-Krohn.

On k-Type 2-Degenerate Slant Helices in 4-Dimensional Minkowski Space-Time

2018 ◽  
Vol 7 (1) ◽  
pp. 147-151 ◽  
Author(s):  
Zühal Küçükarslan Yüzbaşı ◽  
Münevver Yıldırım Yılmaz
Keyword(s):  
Minkowski Space ◽  
Space Time ◽  
Minkowski Space Time ◽  
Dimensional Minkowski Space

HOW SINGULAR A SPACE CAN SUPERSTRINGS THREAD?

1991 ◽  
Vol 06 (03) ◽  
pp. 207-216 ◽  
Author(s):  
TRISTAN HÜBSCH
Keyword(s):  
Minkowski Space ◽  
Moduli Space ◽  
Space Time ◽  
3 Dimensional ◽  
Ricci Flat ◽  
Minkowski Space Time ◽  
Dimensional Minkowski Space

Many superstring models with N=1 supergravity in 4-dimensional Minkowski space-time involve σ-models with complex 3-dimensional, Ricci-flat target manifolds. In general, inclusion of singular target spaces probes the boundary of the moduli space and completes it. Studying suitably singular σ-models, the author found certain criteria for the severity of admissible singularizations.

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