264,779 research outputs found
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
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
Comment on Quantum teleportation via GHZ-like state
Recently Yang et al. [Int. J. Theo. Phys. 48 (2009) 516] have shown that an
unknown qubit can be teleported by using a particular GHZ-like state as quantum
channel. However, there are several errors in the calculation which lead to
incorrect conclusions. The errors have been indicated and corrected. It is also
noted that their scheme and the independently proposed teleportation scheme of
Zhang et al. [Int. J. Theo. Phys. 48 (2009) 3331] uses quantum channel from the
same family and any state of that family may be used for teleportation.Comment: 2 page
Comment on ``Force Balance at the Transition from Selective Withdrawal to Viscous Entrainment
Comment on paper by Blanchette and Zhang, Phys. Rev. Lett. 102, 144501
(2009)
Corrigendum to "An equivalence of categories for graded modules over monomial algebras and path algebras of quivers" [J. Algebra, 353(1) (2012) 249-260]
Our published paper contains an incorrect statement of a result due to Artin
and Zhang. This corrigendum gives the correct statement of their result and
includes a new result that allows us to use their result to prove our main
theorem. Thus the main theorem of our published paper is correct as stated but
its proof must be modified
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