Strange properties of early time evolution of the projection of a state vector

1994 ◽  
Vol 7 (3) ◽  
pp. 285-295
Author(s):  
K. Urbanowski
Keyword(s):  
Time Evolution ◽  
State Vector ◽  
Early Time

Early Time Evolution of Selective Oxidation in a CMnSi AHSS

2019 ◽  
Vol 50 (3) ◽  
pp. 1358-1369
Author(s):  
Mary E. Story ◽  
Bryan A. Webler
Keyword(s):  
Time Evolution ◽  
Selective Oxidation ◽  
Early Time

scholarly journals Early Time Evolution of Turbulence in the Space Environment by Neutral Beam Injection

2020 ◽  
Vol 125 (1) ◽  
Author(s):  
Alex C. Fletcher ◽  
Chris Crabtree ◽  
Joseph Huba ◽  
Gurudas Ganguli ◽  
Carl Siefring
Keyword(s):  
Time Evolution ◽  
Early Time ◽  
Neutral Beam Injection ◽  
Space Environment ◽  
Neutral Beam ◽  
Beam Injection

QUANTUM BROWNIAN AND THE CONSTRAINED PATH INTEGRAL

2008 ◽  
Vol 22 (25n26) ◽  
pp. 4758-4764
Author(s):  
S. BOONCHUI ◽  
V. SA-YAKANIT ◽  
P. PALOTAIDAMKERNG
Keyword(s):  
Quantum System ◽  
Time Evolution ◽  
Path Integral ◽  
State Vector ◽  
Evolution Operator ◽  
Time Evolution Operator

We show that the environment affects a quantum system in the form of the constrained trajectory. Our result allows one to describe the quantum system in terms of stochastic state vector rather than quantum history. Moreover we can alternatively reduce the time evolution operator. Then the trajectory of system is constrained.

EARLY TIME DEPARTURES FROM THE WEISSKOPF-WIGNER DECAY RATE

1993 ◽  
Vol 08 (24) ◽  
pp. 4355-4367 ◽  
Author(s):  
K. URBANOWSKI ◽  
J. SKOREK
Keyword(s):  
Decay Rate ◽  
State Vector ◽  
Early Time ◽  
Time Decay ◽  
Time Decay Rate

The problem of the early time decay rate is studied using the equation for a projection of a state vector. Formulas are found for the decay rate γ(t), generally depending on time, and for early time departures of γ(t) from a rate γ0, given by Weisskopf-Wigner approximation. It is shown that γ(t)→0 as t→0, and γ(t)→γ0 as t→∞. The dependence γ(t) on t is studied numerically in some models.

scholarly journals Multi-scale dynamics of magnetic flux tubes and inverse magnetic energy transfer

2020 ◽  
Vol 86 (4) ◽  
Author(s):  
Muni Zhou ◽  
Nuno F. Loureiro ◽  
Dmitri A. Uzdensky
Keyword(s):  
Magnetic Flux ◽  
Time Evolution ◽  
Magnetic Energy ◽  
Numerical Study ◽  
Three Dimensional ◽  
Early Time ◽  
Small Scale ◽  
Flux Tubes ◽  
Seed Field ◽  
Magnetic Flux Tubes

We report on an analytical and numerical study of the dynamics of a three-dimensional array of identical magnetic flux tubes in the reduced-magnetohydrodynamic description of the plasma. We propose that the long-time evolution of this system is dictated by flux-tube mergers, and that such mergers are dynamically constrained by the conservation of the pertinent (ideal) invariants, viz. the magnetic potential and axial fluxes of each tube. We also propose that in the direction perpendicular to the merging plane, flux tubes evolve in a critically balanced fashion. These notions allow us to construct an analytical model for how quantities such as the magnetic energy and the energy-containing scale evolve as functions of time. Of particular importance is the conclusion that, like its two-dimensional counterpart, this system exhibits an inverse transfer of magnetic energy that terminates only at the system scale. We perform direct numerical simulations that confirm these predictions and reveal other interesting aspects of the evolution of the system. We find, for example, that the early time evolution is characterized by a sharp decay of the initial magnetic energy, which we attribute to the ubiquitous formation of current sheets. We also show that a quantitatively similar inverse transfer of magnetic energy is observed when the initial condition is a random, small-scale magnetic seed field.

EARLY TIME PROPERTIES OF TIME EVOLUTION IN TWO-DIMENSIONAL SUBSPACE AND CP VIOLATION PROBLEM

1993 ◽  
Vol 08 (21) ◽  
pp. 3721-3745 ◽  
Author(s):  
K. URBANOWSKI
Keyword(s):  
Time Evolution ◽  
Early Time ◽  
Dimensional Subspace ◽  
Effective Hamiltonian ◽  
Two Dimensional ◽  
Matrix Elements ◽  
The Matrix ◽  
Long Time ◽  
Time Region ◽  
Short Time

Approximate formulae are given for the effective Hamiltonian H||(t) governing the time evolution in a subspace ℋ|| of the state space ℋ. The properties of matrix elements of H||(t) and the eigenvalue problem for H||(t) are discussed in the case of two-dimensional ℋ||. The eigenvectors of H||(t) for the short time region are found to be different from those for the long time region. The decay law of particles described by the eigenvectors of H||(t) is shown to have the form of the exponential function multiplied by some time-independent factor, equal to 1 only in the case of the [Formula: see text]-invariant theory. Some general properties of the matrix elements of H||(t) are tested in the Lee model.

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