529 research outputs found
Nonassociativity, Dirac monopoles and Aharonov-Bohm effect
The Aharonov-Bohm (AB) effect for the singular string associated with the
Dirac monopole carrying an arbitrary magnetic charge is studied. It is shown
that the emerging difficulties in explanation of the AB effect may be removed
by introducing nonassociative path-dependent wave functions. This provides the
absence of the AB effect for the Dirac string of magnetic monopole with an
arbitrary magnetic charge.Comment: Revised version. Typos corrected. References adde
Non-Hermitian Quantum Systems and Time-Optimal Quantum Evolution
Recently, Bender et al. have considered the quantum brachistochrone problem
for the non-Hermitian -symmetric quantum system and have shown that
the optimal time evolution required to transform a given initial state
into a specific final state can be made
arbitrarily small. Additionally, it has been shown that finding the shortest
possible time requires only the solution of the two-dimensional problem for the
quantum system governed by the effective Hamiltonian acting in the subspace
spanned by and . In this paper, we study a
similar problem for the generic non-Hermitian Hamiltonian, focusing our
attention on the geometric aspects of the problem
Decoherence and Spin Echo in Biological Systems
The spin echo approach is extended to include bio-complexes for which the
interaction with dynamical noise is strong. Significant restoration of the free
induction decay signal due to homogeneous (decoherence) and inhomogeneous
(dephasing) broadening is demonstrated analytically and numerically, for both
an individual dimer of interacting chlorophylls and for an ensemble of dimers.
This approach is based on an exact and closed system of ordinary differential
equations that can be easily solved for a wide range of parameters that are
relevant for bio-applications.Comment: 5 pages, 5 figure
Non-associative geometry and discrete structure of spacetime
A new mathematical theory, non-associative geometry, providing a unified
algebraic description of continuous and discrete spacetime, is introduced.Comment: LATeX2e file, 11 pages, talk given at "Loop's 99 meeting" (Prague,
July 27 - August 1, 1999). To appear in Comment. Math. Univ. Carolin
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