UNIFIED ELECTROWEAK MODEL BASED ON SPACE–TIME AND ISOSPIN SYMMETRIES

2005 ◽  
Vol 20 (01) ◽  
pp. 175-198 ◽  
Author(s):  
D. SPEHLER ◽  
G. C. MARQUES
Keyword(s):  
Degrees Of Freedom ◽  
Space Time ◽  
Scalar Particles ◽  
Symmetry Breakdown ◽  
Vector Bosons ◽  
Rank 2 ◽  
Electroweak Model ◽  
Spontaneous Symmetry Breakdown ◽  
Internal Degrees Of Freedom

We propose a spinorial approach to the unified electroweak interactions, in which no use is made of spontaneous symmetry breakdown. No scalar particles are needed in order to break the symmetry. No reference is made to gauge symmetry. Our approach stresses the role of space–time and isospin symmetries in the build up of the electroweak model. Internal degrees of freedom, such as isospin, are incorporated in the theory by using spinors carrying isospin indices. All vector bosons are described by a rank 2 field in the spinorial and the isospinorial indices. Leptons are accomodated in a rank 1 spinor field and in a rank 2 isospin field as well. The dynamical variables of the theory are the chiral and isochiral components of these fields.

scholarly journals CLASSICAL SOLUTIONS OF GHOST CONDENSATION MODELS

2008 ◽  
Vol 22 (31) ◽  
pp. 3025-3034 ◽  
Author(s):  
MASAHIRO MAENO ◽  
ICHIRO ODA
Keyword(s):  
Degrees Of Freedom ◽  
Goldstone Boson ◽  
Scalar Fields ◽  
Higgs Mechanism ◽  
Space Time ◽  
Classical Solutions ◽  
De Sitter ◽  
Symmetry Breakdown ◽  
Minkowski Space Time ◽  
Spontaneous Symmetry Breakdown

Motivated by ideas obtained from both ghost condensation and gravitational Higgs mechanism, we attempt to find classical solutions in the unitary gauge in general ghost condensation models. It is shown that depending on the form of scalar fields in an action, there are three kinds of exact solutions, which are (anti-) de Sitter space–time, polynomially expanding universes and flat Minkowski space–time. We briefly comment on gravitational Higgs mechanism in these models where we have massive gravitons of five degrees of freedom and one unitary scalar field (Nambu–Goldstone boson) after spontaneous symmetry breakdown of general coordinate reparametrization invariance. The models at hand are free from the problem associated with the non-unitary propagating mode.

Noncommutative scalar field in de Sitter space–time and pair creation process

2021 ◽  
Vol 36 (02) ◽  
pp. 2150011
Author(s):  
Nabil Mehdaoui ◽  
Lamine Khodja ◽  
Salah Haouat
Keyword(s):  
Scalar Field ◽  
Chemical Potential ◽  
De Sitter Space ◽  
Space Time ◽  
Pair Creation ◽  
De Sitter ◽  
Creation Process ◽  
Scalar Particles ◽  
Constant Electromagnetic Field

In this work, we address the process of pair creation of scalar particles in [Formula: see text] de Sitter space–time in presence of a constant electromagnetic field by applying the noncommutativity on the scalar field up to first-order in [Formula: see text]. We calculate the density of particles created in the vacuum by the mean of the Bogoliubov transformations. In contrast to a previous result, we show that noncommutativity contributes to the pair creation process. We find that the noncommutativity plays the same role of chemical potential and gives an important interest for studies at high energies.

Role of internal degrees of freedom in laser-light coherence

1993 ◽  
Vol 47 (2) ◽  
pp. 1274-1277 ◽  
Author(s):  
A. M. Khazanov ◽  
G. A. Koganov ◽  
R. Shuker
Keyword(s):  
Degrees Of Freedom ◽  
Laser Light ◽  
Internal Degrees Of Freedom

scholarly journals A comparison of relaxation processes in structurally related van der Waals glass formers: The role of internal degrees of freedom

2005 ◽  
Vol 122 (7) ◽  
pp. 074506 ◽  
Author(s):  
S. Kahle ◽  
J. Gapinski ◽  
G. Hinze ◽  
A. Patkowski ◽  
G. Meier
Keyword(s):  
Degrees Of Freedom ◽  
Van Der Waals ◽  
Relaxation Processes ◽  
Internal Degrees Of Freedom

Vapor Pressure and Sublimation Rate of Molecular Crystals:  Role of Internal Degrees of Freedom

2007 ◽  
Vol 111 (51) ◽  
pp. 14290-14294 ◽  
Author(s):  
A. Maiti ◽  
L. A. Zepeda-Ruiz ◽  
R. H. Gee ◽  
A. K. Burnham
Keyword(s):  
Vapor Pressure ◽  
Degrees Of Freedom ◽  
Molecular Crystals ◽  
Sublimation Rate ◽  
Internal Degrees Of Freedom

The role of haptic feedback when manipulating nonrigid objects

2012 ◽  
Vol 107 (1) ◽  
pp. 433-441 ◽  
Author(s):  
Frédéric Danion ◽  
Jonathan S. Diamond ◽  
J. Randall Flanagan
Keyword(s):  
Degrees Of Freedom ◽  
Haptic Feedback ◽  
Complex Dynamics ◽  
Movement Time ◽  
Prior Experience ◽  
Learning Rate ◽  
Final Performance ◽  
Subsequent Learning ◽  
Internal Degrees Of Freedom

Humans can learn to manipulate objects with complex dynamics, including nonrigid objects with internal degrees of freedom. The first aim of this study was to assess the contribution of haptic feedback when learning to manipulate a nonrigid object. The second aim was to evaluate how learning without haptic feedback influences subsequent learning with haptic feedback and vice versa. The task involved moving a simulated mass—attached to a grasped handle via a simulated, damped spring—to a target as quickly as possible. In the haptic plus vision (HV) condition, appropriate forces were applied to the handle, which was attached to a robot. In the vision only (V) condition, these forces were turned off. Participants completed 80 trials in each condition, with one-half starting with the HV condition. Both groups exhibited significant learning, as measured by movement time, in both conditions. For the condition performed first, initial performance, learning rate, and final performance were better with haptic feedback. Prior experience in the HV condition led to faster learning and better final performance in the V condition. However, prior experience in the V condition led to slower learning and worse final performance in the HV condition. In the V condition, all participants tended to keep the mass close to the hand. In the HV condition, participants who started with the HV condition allowed the mass to move away from the hand, whereas participants who started with the V condition continued to keep the mass close to the hand. We conclude that haptic feedback as well as prior experience with haptic feedback enhance the ability to control nonrigid objects and that training without haptic feedback can lead to persisting detrimental effects when subsequently dealing with haptic feedback.

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