We study a quantum mechanical system on a singly punctured two-torus with bound states described by the Maass waveforms which are eigenfunctions of the hyperbolic Laplace–Beltrami operator.Since the discrete eigenval...We study a quantum mechanical system on a singly punctured two-torus with bound states described by the Maass waveforms which are eigenfunctions of the hyperbolic Laplace–Beltrami operator.Since the discrete eigenvalues of the Maass cusp form are not known analytically,they are solved numerically using an adapted algorithm of Hejhal and Then to compute Maass cusp forms on the punctured two-torus.We report on the computational results of the lower lying eigenvalues for the punctured two-torus and find that they are doubly-degenerate.We also visualize the eigenstates of selected eigenvalues using GridMathematica.展开更多
A two-qubit system in quantum information theory is the simplest bipartite quantum system and its concurrence for pure and mixed states is well known.As a subset of two-qubit systems,Bell-diagonal states can be depict...A two-qubit system in quantum information theory is the simplest bipartite quantum system and its concurrence for pure and mixed states is well known.As a subset of two-qubit systems,Bell-diagonal states can be depicted by a very simple geometrical representation of a tetrahedron with sides of length 2√2.Based on this geometric representation,we propose a simple approach to randomly generate four mixed Bell decomposable states in which the sum of their concurrence is equal to one.展开更多
We study the interaction between dark energy （DE） and dark matter in the scope of anisotropic Bianchi type-I space-time. First we derive the general form of the DE equation of state （EoS） parameter in both non-int...We study the interaction between dark energy （DE） and dark matter in the scope of anisotropic Bianchi type-I space-time. First we derive the general form of the DE equation of state （EoS） parameter in both non-interacting and interacting cases and then we examine its future by applying a hyperbolic scale factor. It is shown that in the non-interacting case, depending on the value of the anisotropy parameter K, the DE EoS parameter varies from phantom to quintessence whereas in the interacting case the EoS parameter varies in the quintessence region. However, in both cases, the DE EoS parameter ωde ultimately （i.e. at z ： -1） tends to the cosmological constant （ωde = -1）. Moreover, we fix the cosmological bound on the anisotropy parameter K by using recent observational data about the Hubble parameter.展开更多
We study the evolution of the dark energy parameter within the scope of a spatially non-fiat and isotropic Friedmann-Robertson-Walker model filled with barotropic fluid and bulk viscous stresses. We have obtained cosm...We study the evolution of the dark energy parameter within the scope of a spatially non-fiat and isotropic Friedmann-Robertson-Walker model filled with barotropic fluid and bulk viscous stresses. We have obtained cosmological solutions that do not have a Big Rip singularity, and concluded that in both non-interacting and interacting cases the non-fiat open Universe crosses the phantom region. We find that during the evolution of the Universe, the equation of state for dark energy ωD changes from ωDeff 〉 - 1 to ωDeff 〈 - 1, which is consistent with recent observations.展开更多
文摘We study a quantum mechanical system on a singly punctured two-torus with bound states described by the Maass waveforms which are eigenfunctions of the hyperbolic Laplace–Beltrami operator.Since the discrete eigenvalues of the Maass cusp form are not known analytically,they are solved numerically using an adapted algorithm of Hejhal and Then to compute Maass cusp forms on the punctured two-torus.We report on the computational results of the lower lying eigenvalues for the punctured two-torus and find that they are doubly-degenerate.We also visualize the eigenstates of selected eigenvalues using GridMathematica.
文摘A two-qubit system in quantum information theory is the simplest bipartite quantum system and its concurrence for pure and mixed states is well known.As a subset of two-qubit systems,Bell-diagonal states can be depicted by a very simple geometrical representation of a tetrahedron with sides of length 2√2.Based on this geometric representation,we propose a simple approach to randomly generate four mixed Bell decomposable states in which the sum of their concurrence is equal to one.
基金a research fund from the Mahshahr Branch of Islamic Azad University under the project entitled "Interacting Viscous Dark Energy And Cold Dark Matter In An Anisotropic Universe"
文摘We study the interaction between dark energy （DE） and dark matter in the scope of anisotropic Bianchi type-I space-time. First we derive the general form of the DE equation of state （EoS） parameter in both non-interacting and interacting cases and then we examine its future by applying a hyperbolic scale factor. It is shown that in the non-interacting case, depending on the value of the anisotropy parameter K, the DE EoS parameter varies from phantom to quintessence whereas in the interacting case the EoS parameter varies in the quintessence region. However, in both cases, the DE EoS parameter ωde ultimately （i.e. at z ： -1） tends to the cosmological constant （ωde = -1）. Moreover, we fix the cosmological bound on the anisotropy parameter K by using recent observational data about the Hubble parameter.
基金supported by the FRGS Grant by the Ministry of Higher Education,Malaysia under the Project Number 02-10-10-969 FR
文摘We study the evolution of the dark energy parameter within the scope of a spatially non-fiat and isotropic Friedmann-Robertson-Walker model filled with barotropic fluid and bulk viscous stresses. We have obtained cosmological solutions that do not have a Big Rip singularity, and concluded that in both non-interacting and interacting cases the non-fiat open Universe crosses the phantom region. We find that during the evolution of the Universe, the equation of state for dark energy ωD changes from ωDeff 〉 - 1 to ωDeff 〈 - 1, which is consistent with recent observations.
