Relations between the tunneling rate FRW universe are investigated. The namics in such a dynamical system. first law of thermodynamics through and the unified first law of thermodynamics at the apparent horizon of the...Relations between the tunneling rate FRW universe are investigated. The namics in such a dynamical system. first law of thermodynamics through and the unified first law of thermodynamics at the apparent horizon of the tunneling rate arises as a consequence of the unified first law of thermodyAnalysis shows how the tunneling is intimately connected with the unified the principle of conservation of energy.展开更多
We parameterize the Green–Schwarz IIB superstring in the AdS_(3)×S^(3) background under the light cone gauge by the method of Metsaev and Tseytlin in AdS3 and by the method of Rahmfeld and Rajaraman in S3.After ...We parameterize the Green–Schwarz IIB superstring in the AdS_(3)×S^(3) background under the light cone gauge by the method of Metsaev and Tseytlin in AdS3 and by the method of Rahmfeld and Rajaraman in S3.After some calculation,we obtain the corresponding Maurer–Cartan 1−forms and the action.Then we fix two bosonic variables x+=τand y^(5)=σ,perform the partial Legendre transformation of the remaining bosonic variables,and find a Lagrangian that is linear in velocity after eliminating the metric of the world sheet.We also give the Hamiltonian and prove that the system is local and the Poisson bracket of the theory can be well defined.Using these results,one can further study the properties of solution space,solution transformation and the structure of the flat current algebra of the superstring in the AdS_(3)×S^(3) background.展开更多
The lower bounds of the evolution time between two distinguishable states of a system, defined as quantum speed limit time, can characterize the maximal speed of quantum computers and communication channels. We study ...The lower bounds of the evolution time between two distinguishable states of a system, defined as quantum speed limit time, can characterize the maximal speed of quantum computers and communication channels. We study the quantum speed limit time between the composite quantum states and their target states in the presence of nondissipative decoherence.For the initial states with maximally mixed marginals, we obtain the exact expressions of the quantum speed limit time which mainly depend on the parameters of the initial states and the decoherence channels. Furthermore, by calculating the quantum speed limit time for the time-dependent states started from a class of initial states, we discover that the quantum speed limit time gradually decreases in time, and the decay rate of the quantum speed limit time would show a sudden change at a certain critical time. Interestingly, at the same critical time, the composite system dynamics would exhibit a sudden transition from classical decoherence to quantum decoherence.展开更多
We have studied Yang-Baxter deformations of supercoset sigma models with Z4m grading.The deformations are specified by a skew-symmetric classical r-matrix satisfying the classical Yang-Baxter equations.The deformed ac...We have studied Yang-Baxter deformations of supercoset sigma models with Z4m grading.The deformations are specified by a skew-symmetric classical r-matrix satisfying the classical Yang-Baxter equations.The deformed action is constructed and the Lax pair is also presented.When m= 1,our results reduce to those of the type ⅡB Green-Schwarz superstring on AdS5×S5 background recently given by Kawaguchi,Matsumoto and Yoshida.展开更多
基金Supported by National Natural Science Foundation of China under Grant No 10875060, the Natural Science Foundation of Shaanxi Education Bureau of China under Grant No 07JK394, and the NWU Graduate Cross-discipline Fund （08YJC24）.
文摘Relations between the tunneling rate FRW universe are investigated. The namics in such a dynamical system. first law of thermodynamics through and the unified first law of thermodynamics at the apparent horizon of the tunneling rate arises as a consequence of the unified first law of thermodyAnalysis shows how the tunneling is intimately connected with the unified the principle of conservation of energy.
基金by the National Natural Science Foundation of China under Grant Nos 11047179,11075126,11031005 and 10575080the Special Fund for Basic Scientific Research of Central Colleges,Chang’an University+4 种基金the Special Foundation for Basic Research Program of Chang’an Universitythe Open Fund of Key Laboratory for Special Area Highway Engineering(Chang’an University)the Ministry of Education under Grant No CHD2009JC030the Xi’an Shiyou University Science and Technology Foundation under Grant No 2010QN018the NWU Graduate Cross-Discipline Funds under Grant No 09YJC25.
文摘We parameterize the Green–Schwarz IIB superstring in the AdS_(3)×S^(3) background under the light cone gauge by the method of Metsaev and Tseytlin in AdS3 and by the method of Rahmfeld and Rajaraman in S3.After some calculation,we obtain the corresponding Maurer–Cartan 1−forms and the action.Then we fix two bosonic variables x+=τand y^(5)=σ,perform the partial Legendre transformation of the remaining bosonic variables,and find a Lagrangian that is linear in velocity after eliminating the metric of the world sheet.We also give the Hamiltonian and prove that the system is local and the Poisson bracket of the theory can be well defined.Using these results,one can further study the properties of solution space,solution transformation and the structure of the flat current algebra of the superstring in the AdS_(3)×S^(3) background.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61178012 and 11304179)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant Nos.20123705120002 and 20133705110001)+1 种基金the Natural Science Foundation of Shandong Province of China(Grant No.ZR2014AP009)the Scientific Research Foundation of Qufu Normal University
文摘The lower bounds of the evolution time between two distinguishable states of a system, defined as quantum speed limit time, can characterize the maximal speed of quantum computers and communication channels. We study the quantum speed limit time between the composite quantum states and their target states in the presence of nondissipative decoherence.For the initial states with maximally mixed marginals, we obtain the exact expressions of the quantum speed limit time which mainly depend on the parameters of the initial states and the decoherence channels. Furthermore, by calculating the quantum speed limit time for the time-dependent states started from a class of initial states, we discover that the quantum speed limit time gradually decreases in time, and the decay rate of the quantum speed limit time would show a sudden change at a certain critical time. Interestingly, at the same critical time, the composite system dynamics would exhibit a sudden transition from classical decoherence to quantum decoherence.
基金Supported by National Natural Science Foundation of China(11375141,11425522,11547050)Natural Science Foundation of Shaanxi Province(2013JQ1011,2017ZDJC-32,2016JM1027)+3 种基金Special Foundation for Basic Scientific Research of Central Colleges(310812152001,310812172001,2013G1121082,CHD2012JC019)Scientific Research Program Funded by Shaanxi Provincial Education Department(2013JK0628)Xi’an Shiyou University Science and Technology Foundation(2010QN018)partly supported by the Basic Research Foundation of Engineering University of CAPF(WJY-201506)
文摘We have studied Yang-Baxter deformations of supercoset sigma models with Z4m grading.The deformations are specified by a skew-symmetric classical r-matrix satisfying the classical Yang-Baxter equations.The deformed action is constructed and the Lax pair is also presented.When m= 1,our results reduce to those of the type ⅡB Green-Schwarz superstring on AdS5×S5 background recently given by Kawaguchi,Matsumoto and Yoshida.
