Alternative Derivation of the Hu-Paz-Zhang Master Equation for Quantum Brownian Motion

Hu, Paz and Zhang [ B.L. Hu, J.P. Paz and Y. Zhang, Phys. Rev. D {\bf 45} (1992) 2843] have derived an exact master equation for quantum Brownian motion in a general environment via path integral techniques. Their master equation provides a very useful tool to study the decoherence of a quantum system due to the interaction with its environment. In this paper, we give an alternative and elementary derivation of the Hu-Paz-Zhang master equation, which involves tracing the evolution equation for the Wigner function. We also discuss the master equation in some special cases.Comment: 17 pages, Revte

Manni Zhang, soprano and Anna Carl, piano, April 21, 2018

This is the concert program of the Manni Zhang, soprano and Anna Carl, piano performance on Saturday, April 21, 2018 at 8:00 p.m., at the Concert Hall, 855 Commonwealth Avenue. Works performed were La Promessa by Gioachino Rossini, Fiocca La Neve nu Pietro Cimara, Stornello by P. Cimara, Perchè dolce, caro bene by Stefano Donaudy, Ganymed Op. 19, No. 3 D. 544 by Franz Schubert, Liebhaber in allen Gestalten D. 558 by F. Schubert, Im Abendroth D. 799 by F. Schubert, Die Forelle Op. 32 D. 550 by F. Schubert, Vorrei spiegarvi, O Dio by Wolfgang Amadeus Mozart, Fêtes galantes by Claude Debussy, En Sourdine by C. Debussy, Fantoches by C. Debussy, Clair De Lune by C. Debussy, Love by Vittorio Giannini, Tell me, Oh blue blue Sky! by V. Giannini, Sing to My Heart a Song by V. Giannini, and Spring Nostalgia by Huang Zi. Digitization for Boston University Concert Programs was supported by the Boston University Humanities Library Endowed Fund

Reply to Comment on ''Quantum key distribution for d-level systems with generalized Bell states''

In a recent comment \cite{ch1} it has been claimed that an entangled-based quantum key distribution protocol proposed in \cite{zhang} and its generalization to d-level systems in \cite{v1} are insecure against an attack devised by the authors of the comment. We invalidate the arguments of the comment and show that the protocols are still secure.Comment: 4 pages, Latex, no figures, Accepted for Publication in Phys. Rev.

Spin fluctuations influence on quasiparticle spectrum of realistic p-d model

In the present work the multiband p-d model for $CuO_2$-layer is treated. It was shown that for the realistic set of parameters besides Zhang-Rice two-particle singlet there is non-negligible contribution of two-particle triplet state to the top of the valence band. Also shown, that to gain quantitative agreement with experimental data the minimal approximation should include the spin fluctuations beyond the Hubbard-I scheme. Quasiparticle spectrum, obtained in this approximation, is in fairly good agreement with ARPES data on Bi2212 High-$T_c$ compound.Comment: Submitted to ICM 2003 Conference 3 pages, 2 figure

On Real Solutions of the Equation Φ\u3csup\u3e\u3cem\u3et\u3c/em\u3e\u3c/sup\u3e (\u3cem\u3eA\u3c/em\u3e) = 1/\u3cem\u3en\u3c/em\u3e J\u3csub\u3e\u3cem\u3en\u3c/em\u3e\u3c/sub\u3e

For a class of n × n-matrices, we get related real solutions to the matrix equation Φt (A) = 1/n Jn by generalizing the approach of and applying the results of Zhang, Yang, and Cao [SIAM J. Matrix Anal. Appl., 21 (1999), pp. 642–645]. These solutions contain not only those obtained by Zhang, Yang, and Cao but also some which are neither diagonally nor permutation equivalent to those obtained by Zhang, Yang, and Cao. Therefore, the open problem proposed by Zhang, Yang, and Cao in the cited paper is solved

Irrelevance of memory in the minority game

By means of extensive numerical simulations we show that all the distinctive features of the minority game introduced by Challet and Zhang (1997), are completely independent from the memory of the agents. The only crucial requirement is that all the individuals must posses the same information, irrespective of the fact that this information is true or false.Comment: 4 RevTeX pages, 4 figure

Current Issues

Cosmic explosions are observed in many astrophysical environments. They range in scale from hydromagnetic instabilities in the terrestrial magnetotail and solar ``nanoflares'' to cosmological gamma ray bursts, supernovae and the protracted intervals of nuclear activity that produce the giant quasars and radio galaxies. There are many parallels in the analyses of the explosion sites that are highlighted at this workshop, specifically stellar coronae, accretion disks, supernovae and compact objects. In this introductory talk, some general issues are discussed and some more specific questions relating to the individual sites are raised.Comment: To appear in Cosmic Explosions: Proc. 10th Maryland Conference on Astrophysics. Ed. S. Holt and W. Zhang AI

On the self-convolution of generalized Fibonacci numbers

We focus on a family of equalities pioneered by Zhang and generalized by Zao and Wang and hence by Mansour which involves self convolution of generalized Fibonacci numbers. We show that all these formulas are nicely stated in only one equation involving a bivariate ordinary generating function and we give also a formula for the coefficients appearing in that context. As a consequence, we give the general forms for the equalities of Zhang, Zao-Wang and Mansour