Action for the Maxwell–Einstein multiplet from nine-dimensional superspace

1988 ◽  
Vol 66 (9) ◽  
pp. 757-763 ◽  
Author(s):  
Zhou Xiaoan
Keyword(s):  
Extra Dimension ◽  
Degrees Of Freedom ◽  
Dirac Spinor ◽  
Four Dimensions ◽  
Dimensional Spacetime ◽  
Minimal Supergravity ◽  
Starting Point ◽  
Special Case ◽  
Hilbert Action ◽  
Kaluza Klein

The starting point is the Einstein–Hilbert action in nine-dimensional superspace. A special Dirac spinor with only half the degrees of freedom is defined in five-dimensional spacetime. The massless Kaluza–Klein ansatz is used in the dimensional reduction. After this reduction to four dimensions, the action contains a (minimal) supergravity multiplet, a Maxwell multiplet, and a scalar, which corresponds to the oscillation around the extra dimension. The locally supersymmetric (off-mass shell) Maxwell-Einstein action is obtained as a special case of the vanishing oscillation around the extra dimension.

ROLE OF EXTRA DIMENSION IN ACCELERATED EXPANSION

2008 ◽  
Vol 23 (06) ◽  
pp. 909-917 ◽  
Author(s):  
K. D. PUROHIT ◽  
YOGESH BHATT
Keyword(s):  
Cosmological Model ◽  
Extra Dimension ◽  
Accelerated Expansion ◽  
Field Equations ◽  
Four Dimensions ◽  
Scale Factors ◽  
Expansion Of The Universe ◽  
The Universe ◽  
Kaluza Klein

A five-dimensional FRW-type Kaluza–Klein cosmological model is taken to study the role of extra dimension in the expansion of the universe. Relation between scale factors corresponding to conventional four dimensions and the extra dimension has been established. Field equations are solved in order to find out the effect of pressure corresponding to these scale factors. Conditions for accelerated expansion are derived.

scholarly journals Incidences with Curves in $\mathbb{R}^d$

10.37236/5840 ◽  
2016 ◽  
Vol 23 (4) ◽  
Author(s):  
Micha Sharir ◽  
Adam Sheffer ◽  
Noam Solomon
Keyword(s):  
Recent Result ◽  
Degrees Of Freedom ◽  
Algebraic Curves ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Bounded Degree ◽  
Four Dimensions ◽  
Mild Conditions ◽  
Point Line ◽  
Special Case

We prove that the number of incidences between $m$ points and $n$ bounded-degree curves with $k$ degrees of freedom in ${\mathbb R}^d$ is\[ O\left(m^{\frac{k}{dk-d+1}+\varepsilon}n^{\frac{dk-d}{dk-d+1}}+ \sum_{j=2}^{d-1} m^{\frac{k}{jk-j+1}+\varepsilon}n^{\frac{d(j-1)(k-1)}{(d-1)(jk-j+1)}} q_j^{\frac{(d-j)(k-1)}{(d-1)(jk-j+1)}}+m+n\right),\]for any $\varepsilon>0$, where the constant of proportionality depends on $k, \varepsilon$ and $d$, provided that no $j$-dimensional surface of degree $\le c_j(k,d,\varepsilon)$, a constant parameter depending on $k$, $d$, $j$, and $\varepsilon$, contains more than $q_j$ input curves, and that the $q_j$'s satisfy certain mild conditions. This bound generalizes the well-known planar incidence bound of Pach and Sharir to $\mathbb{R}^d$. It generalizes a recent result of Sharir and Solomon concerning point-line incidences in four dimensions (where d=4 and k=2), and partly generalizes a recent result of Guth (as well as the earlier bound of Guth and Katz) in three dimensions (Guth's three-dimensional bound has a better dependency on $q_2$). It also improves a recent d-dimensional general incidence bound by Fox, Pach, Sheffer, Suk, and Zahl, in the special case of incidences with algebraic curves. Our results are also related to recent works by Dvir and Gopi and by Hablicsek and Scherr concerning rich lines in high-dimensional spaces. Our bound is not known to be tight in most cases.

scholarly journals PHENOMENOLOGY FOR AN EXTRA DIMENSION FROM GRAVITATIONAL WAVES PROPAGATION ON A KALUZA–KLEIN SPACE–TIME

2005 ◽  
Vol 14 (01) ◽  
pp. 1-21 ◽  
Author(s):  
EMANUELE ALESCI ◽  
GIOVANNI MONTANI
Keyword(s):  
Gravitational Waves ◽  
Extra Dimension ◽  
Electromagnetic Waves ◽  
Degrees Of Freedom ◽  
Background Field ◽  
Space Time ◽  
Tensor Fields ◽  
Dynamical Degree ◽  
The Waves ◽  
Kaluza Klein

In the present work we analyze the behavior of 5-dimensional (5-d) gravitational waves propagating on a Kaluza–Klein background. We face separately the two cases in which the waves are generated before and after the process of dimensional compactification respectively. We show that if the waves are originated on a 5-d space–time which fulfills the principle of general relativity, then the process of compactification cannot reduce the dynamics to the pure 4-d scalar, vector and tensor degrees of freedom. In particular, while the electromagnetic waves evolve independently, the scalar and tensor fields couple to each other; this feature appears because when the gauge conditions are split, the presence of the scalar ripple prevents the 4-d gravitational waves from becoming traceless. The phenomenological issue of this scheme consists of an anomalous relative amplitude of the two independent polarizations which characterize the 4-d gravitational waves. Such profile of polarization amplitudes, if detected, would outline the extra dimension in a very reliable way, because a wave with non-zero trace cannot arise from ordinary matter sources. We discuss the above mentioned phenomenon either in the case of a unit constant value of the background scalar component (when the geodesic deviation is treated with precise outputs), or assuming such background field as a dynamical degree. Only qualitative conclusion are provided here, because the details of the polarization amplitudes depend on the choice of specific metric forms. Finally, we perturb a real Kaluza–Klein theory showing that in this context, while the electromagnetic waves propagate independently, the 4-d gravitational waves preserve their ordinary structure, while the scalar plays for the role of source.

scholarly journals CAN GRAVITATIONAL WAVES BE MARKERS FOR AN EXTRA-DIMENSION?

2005 ◽  
Vol 14 (06) ◽  
pp. 923-931 ◽  
Author(s):  
EMANUELE ALESCI ◽  
GIOVANNI MONTANI
Keyword(s):  
Gravitational Wave ◽  
Gravitational Waves ◽  
Laboratory Investigation ◽  
Extra Dimension ◽  
Degrees Of Freedom ◽  
High Energy ◽  
Main Issue ◽  
Wave Experiment ◽  
Anomalous Polarization ◽  
Kaluza Klein

The main issue of the present paper is to fix specific features (which turn out being independent of extradimension size) of gravitational waves generated before a dimensional compactification process. Valuable is the possibility to detect our prediction from gravitational wave experiment without high energy laboratory investigation. In particular we show how gravitational waves can bring information on the number of Universe dimensions. Within the framework of Kaluza–Klein hypotheses, a different morphology arises between waves generated before than the compactification process settled down and ordinary 4-dimensional waves. In the former case the scalar and tensor degrees of freedom cannot be resolved. As a consequence if gravitational waves having the feature predicted here were detected (anomalous polarization amplitudes), then they would be reliable markers for the existence of an extra dimension.

scholarly journals A journey to a new stable state—further development of the postoperative recovery concept from day surgical perspective: a qualitative study

BMJ Open ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. e037755
Author(s):  
Ulrica Nilsson ◽  
Maria Jaensson ◽  
Karin Hugelius ◽  
Erebouni Arakelian ◽  
Karuna Dahlberg
Keyword(s):  
Stable State ◽  
Recovery Process ◽  
Well Being ◽  
Day Surgery ◽  
Physical Symptoms ◽  
Postoperative Recovery ◽  
Four Dimensions ◽  
Adult Participants ◽  
Starting Point ◽  
Patients Experience

ObjectiveThis study aims to further develop the concept analysis by Allvin et al in 2007 and Lundmark et al in 2016 from the perspective of day-surgery patients. Also, to describe how patients experience postoperative recovery in relation to the identified dimensions and subdimensions and to interpret the findings in order to get a deeper understanding of the concept postoperative recovery.DesignDescriptive qualitative design with a theoretical thematic analysis.SettingSix day-surgery departments in Sweden.ParticipantsThirty-eight adult participants who had undergone day surgery in Sweden. Participants were purposively selected.ResultsFour dimensions—physical, psychological, social and habitual—were confirmed. A total of eight subdimensions were also confirmed, two from Allvin et al’s study and six from Lundmark et al’s study. Recovery included physical symptoms and challenges coping with and regaining control over symptoms and bodily functions. Both positive and negative emotions were present, and strategies on how to handle emotions and achieve well-being were established. Patients became dependent on others. They coped with and adapted to the recovery process and gradually stabilised, reaching a new stable state.ConclusionPostoperative recovery was described as a process with a clear starting point, and as a dynamic and individual process leading to an experience of a new stable state. The recovery process included physical symptoms, emotions and social and habitual consequences that challenges them. To follow-up and measure all four dimensions of postoperative recovery in order to support and understand the process of postoperative recovery is, therefore, recommended.

PHYSICAL ASPECTS OF SOLITONS IN (4+1) GRAVITY

1995 ◽  
Vol 04 (05) ◽  
pp. 639-659 ◽  
Author(s):  
ANDREW BILLYARD ◽  
PAUL S. WESSON ◽  
DIMITRI KALLIGAS
Keyword(s):  
Physical Properties ◽  
Extra Dimension ◽  
Dimensional Case ◽  
Schwarzschild Solution ◽  
Circular Orbits ◽  
Know How ◽  
Fifth Dimension ◽  
Klein Theory ◽  
Limiting Case ◽  
Kaluza Klein

The augmentation of general relativity’s spacetime by one or more dimensions is described by Kaluza-Klein theory and is within testable limits. Should an extra dimension be observable and significant, it would be beneficial to know how physical properties would differ from “conventional” relativity. In examining the class of five-dimensional solutions analogous to the four-dimensional Schwarzschild solution, we examine where the origin to the system is located and note that it can differ from the four-dimensional case. Furthermore, we study circular orbits and find that the 5D case is much richer; photons can have stable circular orbits in some instances, and stable orbits can exist right to the new origin in others. Finally, we derive both gravitational and inertial masses and find that they do not generally agree, although they can in a limiting case. For all three examinations, it is possible to obtain the four-dimensional results in one limiting case, that of the Schwarzschild solution plus a flat fifth dimension, and that the differences between 4D and 5D occur when the fifth dimension obtains any sort of significance.

scholarly journals BLACK HOLE EVAPORATION BASED UPON A q-DEFORMATION DESCRIPTION

2005 ◽  
Vol 20 (26) ◽  
pp. 6039-6049 ◽  
Author(s):  
XIN ZHANG
Keyword(s):  
Black Hole ◽  
Degrees Of Freedom ◽  
Radiation Spectrum ◽  
Correlation Effect ◽  
Space Time ◽  
Noncommutative Space ◽  
Schwarzschild Black Hole ◽  
Black Hole Evaporation ◽  
Starting Point ◽  
New Distribution

A toy model based upon the q-deformation description for studying the radiation spectrum of black hole is proposed. The starting point is to make an attempt to consider the space–time noncommutativity in the vicinity of black hole horizon. We use a trick that all the space–time noncommutative effects are ascribed to the modification of the behavior of the radiation field of black hole and a kind of q-deformed degrees of freedom are postulated to mimic the radiation particles that live on the noncommutative space–time, meanwhile the background metric is preserved as usual. We calculate the radiation spectrum of Schwarzschild black hole in this framework. The new distribution deviates from the standard thermal spectrum evidently. The result indicates that some correlation effect will be introduced to the system if the noncommutativity is taken into account. In addition, an infrared cutoff of the spectrum is the prediction of the model.

scholarly journals Quark-hadron duality for heavy meson mixings in the ’t Hooft model

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Hiroyuki Umeeda
Keyword(s):  
Heavy Meson ◽  
Four Dimensions ◽  
Width Difference ◽  
Dimensional Spacetime ◽  
Gim Mechanism ◽  
Order Of Magnitude ◽  
Space Function ◽  
Inclusive Analysis ◽  
Phase Space Function ◽  
Hadron Duality

Abstract We study local quark-hadron duality and its violation for the $$ {D}^0-{\overline{D}}^0 $$ D 0 − D ¯ 0 , $$ {B}_d^0-{\overline{B}}_d^0 $$ B d 0 − B ¯ d 0 and $$ {B}_s^0-{\overline{B}}_s^0 $$ B s 0 − B ¯ s 0 mixings in the ’t Hooft model, offering a laboratory to test QCD in two-dimensional spacetime together with the large-Nc limit. With the ’t Hooft equation being numerically solved, the width difference is calculated as an exclusive sum over two-body decays. The obtained rate is compared to inclusive one that arises from four-quark operators to check the validity of the heavy quark expansion (HQE). In view of the observation in four-dimensions that the HQE prediction for the width difference in the $$ {D}^0-{\overline{D}}^0 $$ D 0 − D ¯ 0 mixing is four orders of magnitude smaller than the experimental data, in this work we investigate duality violation in the presence of the GIM mechanism. We show that the order of magnitude of the observable in the $$ {D}^0-{\overline{D}}^0 $$ D 0 − D ¯ 0 mixing is enhanced in the exclusive analysis relative to the inclusive counterpart, when the 4D-like phase space function is used for the inclusive analysis. By contrast, it is shown that for the $$ {B}_d^0-{\overline{B}}_d^0 $$ B d 0 − B ¯ d 0 and $$ {B}_s^0-{\overline{B}}_s^0 $$ B s 0 − B ¯ s 0 mixings, small yet non-negligible corrections to the inclusive result emerge, which are still consistent with what is currently indicated in four-dimensions.

scholarly journals Dimer description of the SU(4) antiferromagnet on the triangular lattice

2020 ◽  
Vol 8 (5) ◽  
Author(s):  
Anna Keselman ◽  
Lucile Savary ◽  
Leon Balents
Keyword(s):  
Phase Diagram ◽  
Triangular Lattice ◽  
Ground State ◽  
Degrees Of Freedom ◽  
Numerical Study ◽  
Spin Model ◽  
Translation Invariance ◽  
Multilayer Graphene ◽  
High Symmetry ◽  
Starting Point

In systems with many local degrees of freedom, high-symmetry points in the phase diagram can provide an important starting point for the investigation of their properties throughout the phase diagram. In systems with both spin and orbital (or valley) degrees of freedom such a starting point gives rise to SU(4)-symmetric models. Here we consider SU(4)-symmetric "spin'' models, corresponding to Mott phases at half-filling, i.e. the six-dimensional representation of SU(4). This may be relevant to twisted multilayer graphene. In particular, we study the SU(4) antiferromagnetic "Heisenberg'' model on the triangular lattice, both in the classical limit and in the quantum regime. Carrying out a numerical study using the density matrix renormalization group (DMRG), we argue that the ground state is non-magnetic. We then derive a dimer expansion of the SU(4) spin model. An exact diagonalization (ED) study of the effective dimer model suggests that the ground state breaks translation invariance, forming a valence bond solid (VBS) with a 12-site unit cell. Finally, we consider the effect of SU(4)-symmetry breaking interactions due to Hund's coupling, and argue for a possible phase transition between a VBS and a magnetically ordered state.

scholarly journals Fermion localization in braneworld teleparallel f(T, B) gravity

2021 ◽  
Vol 81 (4) ◽  
Author(s):  
A. R. P. Moreira ◽  
J. E. G. Silva ◽  
C. A. S. Almeida
Keyword(s):  
Scalar Field ◽  
Yukawa Coupling ◽  
Spinor Field ◽  
Quantum Potential ◽  
Boundary Term ◽  
Dirac Spinor ◽  
Kaluza Klein ◽  
Fermion Localization

AbstractWe study a spin 1/2 fermion in a thick braneworld in the context of teleparallel f(T, B) gravity. Here, f(T, B) is such that $$f_1(T,B)=T+k_1B^{n_1}$$ f 1 ( T , B ) = T + k 1 B n 1 and $$f_2(T,B)=B+k_2T^{n_2}$$ f 2 ( T , B ) = B + k 2 T n 2 , where $$n_{1,2}$$ n 1 , 2 and $$k_{1,2}$$ k 1 , 2 are parameters that control the influence of torsion and the boundary term. We assume Yukawa coupling, where one scalar field is coupled to a Dirac spinor field. We show how the $$n_{1,2}$$ n 1 , 2 and $$k_{1,2}$$ k 1 , 2 parameters control the width of the massless Kaluza–Klein mode, the breadth of non-normalized massive fermionic modes and the properties of the analogue quantum-potential near the origin.

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