FICTON THEORY OF DYNAMICAL SYSTEMS WITH NOISY PARAMETERS

1965 ◽  
Vol 43 (4) ◽  
pp. 619-639 ◽  
Author(s):  
R. C. Bourret
Keyword(s):  
Magnetic Field ◽  
Exact Solution ◽  
Dynamical Systems ◽  
Approximate Solutions ◽  
Frequency Parameter ◽  
Time Dependent ◽  
Quantum Mechanical ◽  
Graphical Comparison ◽  
The One ◽  
Random Fluctuations

The theory of randomly perturbed waves described previously (Bourret 1962a, b) is presented in a form applicable to purely time-dependent systems, classical or quantum mechanical. It is then applied to the problem of a spin-[Formula: see text] dipole in a magnetic field with random fluctuations. One- and two-ficton processes are taken into account and a "renormalization" approximation is given also. Graphical comparison of the approximate solutions with the exact solution is presented. As a classical example, the harmonic oscillator with a noisy frequency parameter is analyzed in both the one- and two-ficton approximations.

An exact solution for electrons in a time-dependent magnetic field

2006 ◽  
Vol 355 (4-5) ◽  
pp. 348-351 ◽  
Author(s):  
D. Laroze ◽  
R. Rivera
Keyword(s):  
Magnetic Field ◽  
Exact Solution ◽  
Time Dependent

scholarly journals A perturbed algorithm for strongly nonlinear variational-like inclusions

2000 ◽  
Vol 62 (3) ◽  
pp. 417-426 ◽  
Author(s):  
C.-H. Lee ◽  
Q. H. Ansari ◽  
J.-C. Yao
Keyword(s):  
Exact Solution ◽  
General Setting ◽  
Approximate Solutions ◽  
Strongly Nonlinear ◽  
Special Cases ◽  
The One

In this paper, we define the concept of η- subdifferential in a more general setting than the one used by Yang and Craven in 1991. By using η-subdifferentiability, we suggest a perturbed algorithm for finding the approximate solutions of strongly nonlinear variational-like inclusions and prove that these approximate solutions converge to the exact solution. Several special cases are also discussed.

A quantum mechanical discussion of Rabi oscillations

2008 ◽  
Vol 86 (8) ◽  
pp. 953-960 ◽  
Author(s):  
G R Hoy ◽  
J Odeurs
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Quantum Mechanics ◽  
Magnetic Resonance ◽  
Spin System ◽  
Magnetic Moment ◽  
Time Dependent ◽  
Quantum Mechanical ◽  
Rabi Oscillations ◽  
Interaction Picture

In 1937, Rabi treated the problem of a magnetic moment in an applied time-dependent magnetic field. This became the well-known magnetic resonance situation. The Hamiltonian is often taken to be [Formula: see text] = – µ · [[Formula: see text]]. In this paper, the Rabi oscillations formula, describing the spin flipping, is derived in an unusual way. The method uses a modification of a method due to Heitler. In the Heitler method, one uses the Interaction Picture of quantum mechanics. Due to the time-dependence in the problem, the usual Heitler method fails. However, the solution is found after quantizing the electromagnetic field. To better understand the origin of the spin flipping, the analogous time-independent problem is also solved. It is made clear that the origin of the Rabi oscillations is not due to the time-dependent magnetic field. The spin flipping is essentially due to the fact that the spin system, when initially prepared, is not in an eigenstate of the Hamiltonian. Thus, as times progresses, the system naturally evolves through the noneigenstate basis states.PACS Nos.: 03.65.–w, 76.20.+q

scholarly journals THE TIME-DEPENDENT ONE-ZONE HADRONIC MODEL: FIRST PRINCIPLES

2012 ◽  
Vol 08 ◽  
pp. 19-24 ◽  
Author(s):  
STAVROS DIMITRAKOUDIS ◽  
MARIA PETROPOULOU ◽  
APOSTOLOS MASTICHIADIS
Keyword(s):  
Magnetic Field ◽  
First Principles ◽  
Kinetic Equations ◽  
Time Dependent ◽  
Accurate Description ◽  
Temporal Behaviour ◽  
Spherical Volume ◽  
The One ◽  
Hadronic Model

We present some results on the radiative signatures of the one zone hadronic model. For this we have solved five spatially averaged, time-dependent coupled kinetic equations which describe the evolution of relativistic protons, electrons, photons, neutrons and neutrinos in a spherical volume containing a magnetic field. Protons are injected and lose energy by synchrotron, photopair and photopion production. We model photopair and photopion using the results of relevant MC codes, like the SOPHIA code in the case of photopion, which give accurate description for the injection of secondaries which then become source functions in their respective equations. This approach allows us to calculate the expected photon and neutrino spectra simultaneously in addition to examining questions like the efficiency and the temporal behaviour of the hadronic models.

An Exact Solution of the Inverse Problem in Heat Conduction Theory and Applications

1964 ◽  
Vol 86 (3) ◽  
pp. 373-380 ◽  
Author(s):  
O. R. Burggraf
Keyword(s):  
Inverse Problem ◽  
Exact Solution ◽  
Heat Conduction ◽  
Boundary Conditions ◽  
Approximate Solutions ◽  
Convergent Series ◽  
Single Location ◽  
Leading Term ◽  
The One ◽  
Direct Problems

An inverse problem in unsteady heat conduction is one for which boundary conditions are prescribed internally, the surface conditions being unknown. By specifying the boundary conditions at a single location, an exact solution is obtained as a rapidly convergent series with the well-known, lumped capacitance approximation as the leading term. Specific forms of the series are determined for sample inverse problems: solid slab, cylinder, sphere, and transpiration-cooled slab. The solution also is applied to direct problems, involving two-point boundary conditions. By truncating the series, approximate solutions of simple form result. The one-term and two-term approximations compare well with exact solutions.

Time-dependent variational principle and self-consistent field equations

1985 ◽  
Vol 98 (2) ◽  
pp. 373-379 ◽  
Author(s):  
V. U. Nazarov
Keyword(s):  
Variational Principle ◽  
Wave Functions ◽  
Time Dependent ◽  
Quantum Mechanical ◽  
Field Equations ◽  
Consistent Field ◽  
Self Consistent Field ◽  
The One ◽  
The Given ◽  
Derivatives Of

In this paper a quantum-mechanical variational principle is proposed, in which the functional varied is the precision, with which the time-dependent Schrödinger equation is satisfied by the wave functions of the given class. Another distinctive feature of our approach is that the independently varied functions are the time derivatives of the one-particle wave functions, of which the wave function of the system is constructed.

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