238 research outputs found
Statistics of photodissociation spectra: nonuniversal properties
We consider the two-point correlation function of the photodissociation cross
section in molecules where the fragmentation process is indirect, passing
through resonances above the dissociation threshold. In the limit of
overlapping resonances, a formula is derived, relating this correlation
function to the behavior of the corresponding classical system. It is shown
that nonuniversal features of the two-point correlation function may have
significant experimental manifestations.Comment: 4 pages, 1 figur
Analisa Penerapan Kinerja Frame Relay pada Pemodelan Jaringan
The development of the internet today has given us so many benefits for the user as well as for industries that use it as a communication medium that is cheap, effective, and efficient. With the development of Internet and various technologies that go with it then it is also directly proportional to the need for the use of the internet is more reliable and reasonable. In the use ofthe internet there are several technologies that can be used, one of which is Frame Relay. Frame Relay network is a network share (shared services) by utilizing the Permanent Virtual Circuit(PVC) so as to ensure minimum access level CIR (Committed Information Rate) specific. Frame Relay is designed to reduce the processing on each node by reducing the format and proceduresused. In this research, frame relay network modeling and analysis of network performance using software GNS3, frame relay network performance will be determined by the parameters of delay,throughput and packet loss. With this study will be obtained performance of some frame relay network model that can be used as a reference in designing the new network
The spectral form factor is not self-averaging
The spectral form factor, k(t), is the Fourier transform of the two level
correlation function C(x), which is the averaged probability for finding two
energy levels spaced x mean level spacings apart. The average is over a piece
of the spectrum of width W in the neighborhood of energy E0. An additional
ensemble average is traditionally carried out, as in random matrix theory.
Recently a theoretical calculation of k(t) for a single system, with an energy
average only, found interesting nonuniversal semiclassical effects at times t
approximately unity in units of {Planck's constant) /(mean level spacing). This
is of great interest if k(t) is self-averaging, i.e, if the properties of a
typical member of the ensemble are the same as the ensemble average properties.
We here argue that this is not always the case, and that for many important
systems an ensemble average is essential to see detailed properties of k(t). In
other systems, notably the Riemann zeta function, it is likely possible to see
the properties by an analysis of the spectrum.Comment: 4 pages, RevTex, no figures, submitted to Phys. Rev. Lett., permanent
e-mail address, [email protected]
Orbital Magnetism of 2D Chaotic Lattices
We study the orbital magnetism of 2D lattices with chaotic motion of
electrons withing a primitive cell. Using the temperature diagrammatic
technique we evaluate the averaged value and rms fluctuation of magnetic
response in the diffusive regime withing the model of non-interacting
electrons. The fluctuations of magnetic susceptibility turn out to be large and
at low temperature can be of the order of , where
is the Fermi wavevector, is the mean free path, and is
the Landau susceptibility. In the certain region of magnetic fields the
paramagnetic contribution to the averaged response is field independent and
larger than the absolute value of Landau response.Comment: 6 pages, Latex file, figures available upon reques
Scars of Invariant Manifolds in Interacting Chaotic Few-Body Systems
We present a novel extension of the concept of scars for the wave functions
of classically chaotic few-body systems of identical particles with rotation
and permutation symmetry. Generically there exist manifolds in classical phase
space which are invariant under the action of a common subgroup of these two
symmetries. Such manifolds are associated with highly symmetric configurations.
If sufficiently stable, the quantum motion on such manifolds displays a notable
enhancement of the revival in the autocorrelation function which is not
directly associated with individual periodic orbits. Rather, it indicates some
degree of localization around an invariant manifold which has collective
characteristics that should be experimentally observable.Comment: 4 pages, RevTeX, 4 PS/EPS-figures, uses psfig.sty, quantum
computation changed, to be published in Physical Review Letter
Semiclassical Field Theory Approach to Quantum Chaos
We construct a field theory to describe energy averaged quantum statistical
properties of systems which are chaotic in their classical limit. An expression
for the generating function of general statistical correlators is presented in
the form of a functional supermatrix nonlinear -model where the
effective action involves the evolution operator of the classical dynamics.
Low-lying degrees of freedom of the field theory are shown to reflect the
irreversible classical dynamics describing relaxation of phase space
distributions. The validity of this approach is investigated over a wide range
of energy scales. As well as recovering the universal long-time behavior
characteristic of random matrix ensembles, this approach accounts correctly for
the short-time limit yielding results which agree with the diagonal
approximation of periodic orbit theory.Comment: uuencoded file, 21 pages, latex, one eps figur
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