3,221 research outputs found
Correlations between spectra with different symmetry: any chance to be observed?
A standard assumption in quantum chaology is the absence of correlation
between spectra pertaining to different symmetries. Doubts were raised about
this statement for several reasons, in particular, because in semiclassics
spectra of different symmetry are expressed in terms of the same set of
periodic orbits. We reexamine this question and find absence of correlation in
the universal regime. In the case of continuous symmetry the problem is reduced
to parametric correlation, and we expect correlations to be present up to a
certain time which is essentially classical but larger than the ballistic time
Quantum and classical echoes in scattering systems described by simple Smale horseshoes
We explore the quantum scattering of systems classically described by binary
and other low order Smale horseshoes, in a stage of development where the
stable island associated with the inner periodic orbit is large, but chaos
around this island is well developed. For short incoming pulses we find
periodic echoes modulating an exponential decay over many periods. The period
is directly related to the development stage of the horseshoe. We exemplify our
studies with a one-dimensional system periodically kicked in time and we
mention possible experiments.Comment: 7 pages with 6 reduced quality figures! Please contact the authors
([email protected]) for an original good quality pre-prin
Ancient Egypt 1916 Part 2
Part 2 of the 1916 Ancient Egypt books. Contents include the Gorringe collection, an early figure of Taurt, Egypt in the Grail Romance, and the queenly title, XXIInd dynasty.https://knowledge.e.southern.edu/kweeks_coll/1006/thumbnail.jp
Spectral sum rules and finite volume partition function in gauge theories with real and pseudoreal fermions
Based on the chiral symmetry breaking pattern and the corresponding
low-energy effective lagrangian, we determine the fermion mass dependence of
the partition function and derive sum rules for eigenvalues of the QCD Dirac
operator in finite Euclidean volume. Results are given for and for
Yang-Mills theory coupled to several light adjoint Majorana fermions. They
coincide with those derived earlier in the framework of random matrix theory.Comment: 22p., SUNY-NTG-94/18, TPI-MINN-94/10-
Self-pulsing effect in chaotic scattering
We study the quantum and classical scattering of Hamiltonian systems whose
chaotic saddle is described by binary or ternary horseshoes. We are interested
in parameters of the system for which a stable island, associated with the
inner fundamental periodic orbit of the system exists and is large, but chaos
around this island is well developed. In this situation, in classical systems,
decay from the interaction region is algebraic, while in quantum systems it is
exponential due to tunneling. In both cases, the most surprising effect is a
periodic response to an incoming wave packet. The period of this self-pulsing
effect or scattering echoes coincides with the mean period, by which the
scattering trajectories rotate around the stable orbit. This period of rotation
is directly related to the development stage of the underlying horseshoe.
Therefore the predicted echoes will provide experimental access to topological
information. We numerically test these results in kicked one dimensional models
and in open billiards.Comment: Submitted to New Journal of Physics. Two movies (not included) and
full-resolution figures are available at http://www.cicc.unam.mx/~mejia
‘My favourite things to do’ and ‘my favourite people’: Exploring salient aspects of children’s self-concept
This study explores the potential of the ‘draw-and-write’ method for inviting children to communicate salient aspects of their self-concept. Irish primary school children aged 10–13 years drew and wrote about their favourite people and things to do (social and active self). Children drew and described many salient activities (39 in total) and people – including pets. Results suggest that widely used, adult-constructed self-esteem scales for children, while multidimensional, are limited, and that ‘draw-and-write’ is an effective multimodal method with which children can express their social and active self-concepts
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
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