scholarly journals A GEOMETRICAL APPROACH TO TIME-DEPENDENT GAUGE-FIXING

1993 ◽  
Vol 08 (23) ◽  
pp. 4055-4069 ◽  
Author(s):  
JONATHAN M. EVANS ◽  
PHILIP A. TUCKEY
Keyword(s):  
Phase Space ◽  
Hamiltonian Function ◽  
Time Dependent ◽  
Geometrical Approach ◽  
Dirac Bracket ◽  
Special Cases ◽  
Gauge Fixing ◽  
Necessary And Sufficient ◽  
Geometrical Formulation ◽  
Time Evolution Equation

When a Hamiltonian system is subject to constraints which depend explicitly on time, difficulties can arise in attempting to reduce the system to its physical phase space. Specifically, it is nontrivial to restrict the system in such a way that one can find a Hamiltonian time-evolution equation involving the Dirac bracket. Using a geometrical formulation, we derive an explicit condition which is both necessary and sufficient for this to be possible, and we give a formula defining the resulting Hamiltonian function. Some previous results are recovered as special cases.

THE QUADRATIC TIME-DEPENDENT HAMILTONIAN: EVOLUTION OPERATOR, SQUEEZING REGIONS IN PHASE SPACE AND TRAJECTORIES

1994 ◽  
Vol 08 (11n12) ◽  
pp. 1563-1576 ◽  
Author(s):  
S.S. MIZRAHI ◽  
M.H.Y. MOUSSA ◽  
B. BASEIA
Keyword(s):  
Phase Space ◽  
Unitary Transformation ◽  
Uniform Magnetic Field ◽  
Evolution Operator ◽  
Single Mode ◽  
Time Dependent ◽  
Special Cases ◽  
Complete Set ◽  
Hamiltonian Evolution ◽  
General Time

We consider the most general Time-Dependent (TD) quadratic Hamiltonian written in terms of the bosonic operators a and a+, which may represent either a charged particle subjected to a harmonic motion, immersed in a TD uniform magnetic field, or a single mode photon field going through a squeezing medium. We solve the TD Schrödinger equation by a method that uses, sequentially, a TD unitary transformation and the diagonalization of a TD invariant, and we verify that the exact solution is a complete set of TD states. We also obtain the evolution operator which is essential to express operators in the Heisenberg picture. The variances of the quadratures are calculated and a phase space of parameters introduced, in which we identify squeezing regions. The results for some special cases are presented and as an illustrative example the parametric oscillator is revisited and the trajectories in phase space drawn.

Autonomous Geometrical Mechanics

2018 ◽  
Author(s):  
Peter Mann
Keyword(s):  
Phase Space ◽  
Contact Structure ◽  
Invariant Tori ◽  
Time Dependent ◽  
Contact Structures ◽  
Natural Setting ◽  
Adiabatic Invariance ◽  
Jet Bundle ◽  
Integrability Theorem ◽  
Extended Phase

This chapter examines the structure of the phase space of an integrable system as being constructed from invariant tori using the Arnold–Liouville integrability theorem, and periodic flow and ergodic flow are investigated using action-angle theory. Time-dependent mechanics is formulated by extending the symplectic structure to a contact structure in an extended phase space before it is shown that mechanics has a natural setting on a jet bundle. The chapter then describes phase space of integrable systems and how tori behave when time-dependent dynamics occurs. Adiabatic invariance is discussed, as well as slow and fast Hamiltonian systems, the Hannay angle and counter adiabatic terms. In addition, the chapter discusses foliation, resonant tori, non-resonant tori, contact structures, Pfaffian forms, jet manifolds and Stokes’s theorem.

scholarly journals Time-dependent relaxed magnetohydrodynamics: Inclusion of cross helicity constraint using phase-space action

2020 ◽  
Vol 27 (6) ◽  
pp. 062504 ◽  
Author(s):  
R. L. Dewar ◽  
J. W. Burby ◽  
Z. S. Qu ◽  
N. Sato ◽  
M. J. Hole
Keyword(s):  
Phase Space ◽  
Time Dependent ◽  
Space Action

scholarly journals SELF-DUALITY OF SUPER D3-BRANE ACTION ON AdS5×S5 BACKGROUND

1999 ◽  
Vol 14 (05) ◽  
pp. 327-335 ◽  
Author(s):  
T. KIMURA
Keyword(s):  
Gauge Field ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Duality Transformation ◽  
Self Duality ◽  
World Volume ◽  
The World ◽  
Gauge Fixing ◽  
Necessary And Sufficient ◽  
Brane Action

We show that the super D3-brane action on AdS5×S5 background recently constructed by Metsaev and Tseytlin is exactly invariant under the combination of the electric–magnetic duality transformation of the world-volume gauge field and the SO(2) rotation of N=2 spinor coordinates. The action is shown to satisfy the Gaillard–Zumino duality condition, which is a necessary and sufficient condition for an action to be self-dual. Our proof needs no gauge fixing for the κ-symmetry.

scholarly journals A Critical Review of Works Pertinent to the Einstein-Bohr Debate and Bell’s Theorem

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 163
Author(s):  
Karl Hess
Keyword(s):  
Quantum Theory ◽  
Physical Reality ◽  
Point Of View ◽  
Statistical Sampling ◽  
Necessary And Sufficient Condition ◽  
Special Cases ◽  
General Physical ◽  
Necessary And Sufficient ◽  
Physical Features ◽  
Chsh Inequalities

This review is related to the Einstein-Bohr debate and to Einstein–Podolsky–Rosen’s (EPR) and Bohm’s (EPRB) Gedanken-experiments as well as their realization in actual experiments. I examine a significant number of papers, from my minority point of view and conclude that the well-known theorems of Bell and Clauser, Horne, Shimony and Holt (CHSH) deal with mathematical abstractions that have only a tenuous relation to quantum theory and the actual EPRB experiments. It is also shown that, therefore, Bell-CHSH cannot be used to assess the nature of quantum entanglement, nor can physical features of entanglement be used to prove Bell-CHSH. Their proofs are, among other factors, based on a statistical sampling argument that is invalid for general physical entities and processes and only applicable for finite “populations”; not for elements of physical reality that are linked, for example, to a time-like continuum. Bell-CHSH have, furthermore, neglected the subtleties of the theorem of Vorob’ev that includes their theorems as special cases. Vorob’ev found that certain combinatorial-topological cyclicities of classical random variables form a necessary and sufficient condition for the constraints that are now known as Bell-CHSH inequalities. These constraints, however, must not be linked to the observables of quantum theory nor to the actual EPRB experiments for a variety of reasons, including the existence of continuum-related variables and appropriate considerations of symmetry.

scholarly journals BRST Quantization of the Proca Model Based on the BFT and the BFV Formalism

1997 ◽  
Vol 12 (23) ◽  
pp. 4217-4239 ◽  
Author(s):  
Yong-Wan Kim ◽  
Mu-In Park ◽  
Young-Jai Park ◽  
Sean J. Yoon
Keyword(s):  
Phase Space ◽  
Brst Quantization ◽  
Brst Symmetry ◽  
Mass Term ◽  
Class Constraint ◽  
Extended Phase ◽  
Breaking Effect ◽  
Linear Character ◽  
Constraint System ◽  
Gauge Fixing

The BRST quantization of the Abelian Proca model is performed using the Batalin–Fradkin–Tyutin and the Batalin-Fradkin-Vilkovisky formalism. First, the BFT Hamiltonian method is applied in order to systematically convert a second class constraint system of the model into an effectively first class one by introducing new fields. In finding the involutive Hamiltonian we adopt a new approach which is simpler than the usual one. We also show that in our model the Dirac brackets of the phase space variables in the original second class constraint system are exactly the same as the Poisson brackets of the corresponding modified fields in the extended phase space due to the linear character of the constraints comparing the Dirac or Faddeev–Jackiw formalisms. Then, according to the BFV formalism we obtain that the desired resulting Lagrangian preserving BRST symmetry in the standard local gauge fixing procedure naturally includes the Stückelberg scalar related to the explicit gauge symmetry breaking effect due to the presence of the mass term. We also analyze the nonstandard nonlocal gauge fixing procedure.

CHAOTIC SCATTERING IN TIME-DEPENDENT HAMILTONIAN SYSTEMS

1991 ◽  
Vol 01 (03) ◽  
pp. 667-679 ◽  
Author(s):  
YING-CHENG LAI ◽  
CELSO GREBOGI
Keyword(s):  
Phase Space ◽  
Measure Zero ◽  
Invariant Set ◽  
Time Dependent ◽  
Invariant Sets ◽  
Physical Origin ◽  
Chaotic Scattering ◽  
Periodic Oscillations ◽  
Surface Of Section ◽  
Oscillating Potential

We consider the classical scattering of particles in a one-degree-of-freedom, time-dependent Hamiltonian system. We demonstrate that chaotic scattering can be induced by periodic oscillations in the position of the potential. We study the invariant sets on a surface of section for different amplitudes of the oscillating potential. It is found that for small amplitudes, the phase space consists of nonescaping KAM islands and an escaping set. The escaping set is made up of a nonhyperbolic set that gives rise to chaotic scattering and remains of KAM islands. For large amplitudes, the phase space contains a Lebesgue measure zero invariant set that gives rise to chaotic scattering. In this regime, we also discuss the physical origin of the Cantor set responsible for the chaotic scattering and calculate its fractal dimension.

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