scholarly journals Ordered space-time structures: Quantum carpets from Gaussian sum theory

2019 ◽  
Vol 62 (7) ◽  
Author(s):  
HuiXin Xiong ◽  
XueKe Song ◽  
HuaiYang Yuan ◽  
DaPeng Yu ◽  
ManHong Yung
Keyword(s):  
Space Time ◽  
Gaussian Sum ◽  
Ordered Space ◽  
Time Structures

scholarly journals The shape dynamics description of gravity

2015 ◽  
Vol 93 (9) ◽  
pp. 956-962 ◽  
Author(s):  
Tim Koslowski
Keyword(s):  
Minkowski Space ◽  
Space Time ◽  
Point Of View ◽  
Small Scale ◽  
Shape Dynamics ◽  
Quantum Particles ◽  
Minkowski Space Time ◽  
Time Structures ◽  
Geometric Picture

Classical gravity can be described as a relational dynamical system without ever appealing to space–time or its geometry. This description is the so-called shape dynamics description of gravity. The existence of relational first principles from which the shape dynamics description of gravity can be derived is a motivation to consider shape dynamics (rather than general relativity) as the fundamental description of gravity. Adopting this point of view leads to the question: What is the role of space–time in the shape dynamics description of gravity? This question contains many aspects: Compatibility of shape dynamics with the description of gravity in terms of space–time geometry, the role of local Minkowski space, universality of space–time geometry and the nature of quantum particles, which can no longer be assumed to be irreducible representations of the Poincaré group. In this contribution I derive effective space–time structures by considering how matter fluctuations evolve along with shape dynamics. This evolution reveals an “experienced space–time geometry.” This leads (in an idealized approximation) to local Minkowski space and causal relations. The small-scale structure of the emergent geometric picture depends on the specific probes used to experience space–time, which limits the applicability of effective space–time to describe shape dynamics. I conclude with discussing the nature of quantum fluctuations (particles) in shape dynamics and how local Minkowski space–time emerges from the evolution of quantum particles.

A classification of space-time structures

1976 ◽  
Vol 10 (3) ◽  
pp. 297-310 ◽  
Author(s):  
Andrzej Trautman
Keyword(s):  
Space Time ◽  
Time Structures

Structure of the Madden–Julian Oscillation in the Superparameterized CAM

2009 ◽  
Vol 66 (11) ◽  
pp. 3277-3296 ◽  
Author(s):  
James J. Benedict ◽  
David A. Randall
Keyword(s):  
Boundary Layer ◽  
General Circulation ◽  
Deep Convection ◽  
Circulation Model ◽  
Grid Cell ◽  
Atmospheric Model ◽  
Space Time ◽  
Madden Julian Oscillation ◽  
Moist Convection ◽  
Time Structures

Abstract The detailed dynamic and thermodynamic space–time structures of the Madden–Julian oscillation (MJO) as simulated by the superparameterized Community Atmosphere Model version 3.0 (SP-CAM) are analyzed. Superparameterization involves substituting conventional boundary layer, moist convection, and cloud parameterizations with a configuration of cloud-resolving models (CRMs) embedded in each general circulation model (GCM) grid cell. Unlike most GCMs that implement conventional parameterizations, the SP-CAM displays robust atmospheric variability on intraseasonal space and time (30–60 days) scales. The authors examine a 19-yr SP-CAM simulation based on the Atmospheric Model Intercomparison Project protocol, forced by prescribed sea surface temperatures. Overall, the space–time structures of MJO convective disturbances are very well represented in the SP-CAM. Compared to observations, the model produces a similar vertical progression of increased moisture, warmth, and heating from the boundary layer to the upper troposphere as deep convection matures. Additionally, important advective and convective processes in the SP-CAM compare favorably with those in observations. A deficiency of the SP-CAM is that simulated convective intensity organized on intraseasonal space–time scales is overestimated, particularly in the west Pacific. These simulated convective biases are likely due to several factors including unrealistic boundary layer interactions, a lack of weakening of the simulated disturbance over the Maritime Continent, and mean state differences.

Space-time structures of earthquakes

2009 ◽  
Vol 105 (1-2) ◽  
pp. 69-83 ◽  
Author(s):  
T. N. Krishnamurti ◽  
Ruby Krishnamurti ◽  
Anitha D. Sagadevan ◽  
Arindam Chakraborty ◽  
William K. Dewar ◽  
...  
Keyword(s):  
Space Time ◽  
Time Structures

scholarly journals Notes on Conservation Laws, Equations of Motion of Matter, and Particle Fields in Lorentzian and Teleparallel de Sitter Space-Time Structures

2016 ◽  
Vol 2016 ◽  
pp. 1-27 ◽  
Author(s):  
Waldyr A. Rodrigues ◽  
Samuel A. Wainer
Keyword(s):  
Equations Of Motion ◽  
Killing Vector ◽  
De Sitter Space ◽  
Momentum Conservation ◽  
Space Time ◽  
Relativity Theory ◽  
De Sitter ◽  
Metric Tensor ◽  
Clifford Bundle ◽  
Time Structures

We discuss the physics of interacting fields and particles living in a de Sitter Lorentzian manifold (dSLM), a submanifold of a 5-dimensional pseudo-Euclidean (5dPE) equipped with a metric tensor inherited from the metric of the 5dPE space. The dSLM is naturally oriented and time oriented and is the arena used to study the energy-momentum conservation law and equations of motion for physical systems living there. Two distinct de Sitter space-time structuresMdSLandMdSTPare introduced given dSLM, the first equipped with the Levi-Civita connection of its metric field and the second with a metric compatible parallel connection. Both connections are used only as mathematical devices. Thus, for example,MdSLis not supposed to be the model of any gravitational field in the General Relativity Theory (GRT). Misconceptions appearing in the literature concerning the motion of free particles in dSLM are clarified. Komar currents are introduced within Clifford bundle formalism permitting the presentation of Einstein equation as a Maxwell like equation and proving that in GRT there are infinitely many conserved currents. We prove that in GRT even when the appropriate Killing vector fields exist it is not possible to define a conserved energy-momentum covector as in special relativistic theories.

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