SPACE-TIME PROPAGATION OF CONFINED GLUONS

1989 ◽  
Vol 04 (15) ◽  
pp. 3807-3818 ◽  
Author(s):  
L. S. CELENZA ◽  
C. M. SHAKIN ◽  
HUI-WEN WANG ◽  
XIN-HUA YANG
Keyword(s):  
Order Parameter ◽  
Gluon Condensate ◽  
Delta Function ◽  
Space Time ◽  
Coordinate Space ◽  
Dynamical Mass ◽  
Momentum Mode ◽  
Zero Momentum ◽  
Time Propagation

We assume that there is gluon condensate in the zero-momentum mode in the QCD ground state. A lowest-order calculation in terms of a condensate order parameter leads to a dynamical mass for gluons via the Schwinger mechanism and a gluon propagator with no on-mass-shell singularities — that is, the gluon is a "nonpropagating mode" in the gluon condensate. We transform our momentum-space propagator into coordinate space and find that the propagator has essentially the same delta-function light-cone singularities as the free propagator. However, in contrast to a theory without confinement, we show that the propagator exhibits exponential decay, both for time-like and space-like propagation. In this manner, we obtain a space-time characterization of the confinement phenomenon in terms of an order parameter of the condensate.

scholarly journals Exploring the Characteristics and Influencing Factors of Leisure Walking Based on the Demand of Behavior

2021 ◽  
Vol 13 (8) ◽  
pp. 4105
Author(s):  
Yupei Jiang ◽  
Honghu Sun
Keyword(s):  
Health Benefits ◽  
Health Benefit ◽  
Public Health Research ◽  
Space Time ◽  
Time Behavior ◽  
Walking Behavior ◽  
Face To Face ◽  
Residential Neighborhood ◽  
The Impact

Leisure walking has been an important topic in space-time behavior and public health research. However, prior studies pay little attention to the integration and the characterization of diverse and multilevel demands of leisure walking. This study constructs a theoretical framework of leisure walking behavior demands from three different dimensions and levels of activity participation, space-time opportunity, and health benefit. On this basis, through a face-to-face survey in Nanjing, China (N = 1168, 2017–2018 data), this study quantitatively analyzes the characteristics of leisure walking demands, as well as the impact of the built environment and individual factors on it. The results show that residents have a high demand for participation and health benefits of leisure walking. The residential neighborhood provides more space opportunities for leisure walking, but there is a certain constraint on the choice of walking time. Residential neighborhood with medium or large parks is more likely to satisfy residents’ demands for engaging in leisure walking and obtaining high health benefits, while neighborhood with a high density of walking paths tends to limit the satisfaction of demands for space opportunity and health benefit. For residents aged 36 and above, married, or retired, their diverse demands for leisure walking are more likely to be fulfilled, while those with high education, medium-high individual income, general and above health status, or children (<18 years) are less likely to be fulfilled. These finding that can have important implications for the healthy neighborhood by fully considering diverse and multilevel demands of leisure walking behavior.

scholarly journals WEYL GEOMETRY AS CHARACTERIZATION OF SPACE-TIME

2011 ◽  
Vol 03 ◽  
pp. 87-97 ◽  
Author(s):  
F. P. POULIS ◽  
J. M. SALIM
Keyword(s):  
General Relativity ◽  
Scalar Field ◽  
Riemannian Geometry ◽  
Axiomatic Approach ◽  
Space Time ◽  
Weyl Geometry ◽  
Test Particles ◽  
Variational Formalism ◽  
Physical Fields

Motivated by an axiomatic approach to characterize space-time it is investigated a reformulation of Einstein's gravity where the pseudo-riemannian geometry is substituted by a Weyl one. It is presented the main properties of the Weyl geometry and it is shown that it gives extra contributions to the trajectories of test particles, serving as one more motivation to study general relativity in Weyl geometry. It is introduced its variational formalism and it is established the coupling with other physical fields in such a way that the theory acquires a gauge symmetry for the geometrical fields. It is shown that this symmetry is still present for the red-shift and it is concluded that for cosmological models it opens the possibility that observations can be fully described by the new geometrical scalar field. It is concluded then that this reformulation, although representing a theoretical advance, still needs a complete description of their objects.

Momentum space techniques for curved space–time quantum field theory

1979 ◽  
Vol 367 (1728) ◽  
pp. 123-141 ◽  
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Momentum Space ◽  
Nuclear Physics ◽  
Space Time ◽  
Coordinate Space ◽  
Quantum Field ◽  
Curved Space ◽  
Time Quantum ◽  
Space Formulation

A momentum space formulation of curved space–time quantum field theory is presented. Such a formulation allows the riches of momentum space calculational techniques already existing in nuclear physics to be exploited in the application of quantum field theory to cosmology and astrophysics. It is demonstrated that one such technique can allow exact, or very accu­rate approximate, results to be obtained in cases which are intractable in coordinate space. An efficient method of numerical solution is also described.

Electrical Characterization of E7 Liquid Crystal Molecules under the Impact of an External Electric Field (THz): A Theoretical approach

2020 ◽  
Vol 15 (2) ◽  
pp. 95-101
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Order Parameter ◽  
Optical Switching ◽  
Rapid Change ◽  
Electrical Characterization ◽  
Optical Switching Devices ◽  
The Impact ◽  
Orientation Of Molecules

In this work, different parameters of E7 liquid crystal (LC) have been calculated under the influence of an electric field in THz frequency. The E7 LC parameters have positive as well as negative values of order parameter and birefringence under the influence for an electric field. The director angle of E7 LC shows fast fluctuations above the angle θ=45° and due to rapid change in the orientation of molecules, fast electro-optical switching devices based on E7 LC can be designed. The refractive index of the E7 LC maintains stability in THz frequency.

Spinning strings of the Neveu-Schwarz-Ramond type in 3, 4, 6, and 10 space-time dimensions

1999 ◽  
Vol 77 (6) ◽  
pp. 427-446
Author(s):  
S B Phillips
Keyword(s):  
Degrees Of Freedom ◽  
Lagrangian Density ◽  
Dimensional Space ◽  
Equations Of Motion ◽  
Physical Space ◽  
Space Time ◽  
Coordinate Space ◽  
Time Dimension ◽  
Light Cone Gauge ◽  
Fermionic Sector

A model of a spinning string with an internal coordinate index is proposed and studied. When the action for this model is taken to be diagonal in this internal coordinate space and quantized in the light-cone gauge it is found to be Lorentz covariant in four-dimensional space-time provided that the internal coordinate space is four dimensional.This combination of space-time dimension, D, and internal coordinate space dimension, N, is just one of four possible sets, the other three corresponding to D = 3, 6, and 10, precisely the same values for which it is possible to formulate Yang-Mills theories with simple supersymmetry. By comparing the number of propagating degrees of freedom at the zero-mass level in the open string bosonic and fermionic sectors it is found that a supersymmetric interpretation of this model is possible provided that all physical states in the bosonic sector have even G-parity and the ground-state spin or in the fermionic sector have positive chirality. A possible interpretation of the connection betweenthe N components of each of the D space-time coordinates is presentedon the basis that the space-time coordinates are scalars in the internal coordinate space. This interpretation would appear to be reasonable given the fact that the field variables in the Lagrangian density do not necessarily have to represent physically measurable quantities but can, instead, only represent physically measurable quantities when combined in some manner, the simplest of which being a linear combination. The Lagrangian density simply produces the equations of motion and the constraint equations for the independent variables, only linear combinations of which represent the four dimensions of physical space-time.PACS Nos.: 11.17.+y, 11.10.Qr, 1.30.Cp, 11.30.Pb

scholarly journals Characterization of online groups along space, time, and social dimensions

2014 ◽  
Vol 3 (1) ◽  
Author(s):  
David Martin-Borregon ◽  
Luca Maria Aiello ◽  
Przemyslaw Grabowicz ◽  
Alejandro Jaimes ◽  
Ricardo Baeza-Yates
Keyword(s):  
Space Time ◽  
Social Dimensions ◽  
Online Groups

Stochastic characterization of space-time precipitation: Implications for remote sensing

1994 ◽  
Vol 17 (1-2) ◽  
pp. 47-59 ◽  
Author(s):  
Juan B. Valdés ◽  
Eunho Ha ◽  
Chulsang Yoo ◽  
Gerald R. North
Keyword(s):  
Remote Sensing ◽  
Space Time ◽  
Stochastic Characterization
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