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991.
H.?Mohseni?SadjadiEmail author M.?Alimohammadi 《General Relativity and Gravitation》2005,37(11):1809-1822
We obtain the electrostatic energy of two opposite charges near the horizon of stationary black holes in the massive Schwinger
model. Besides the confining aspects of the model, we discuss the Bekenstein entropy upper bound of a charged object using
the generalized second law. We show that despite the massless case, in the massive Schwinger model the entropy of the black
hole and consequently the Bekenstein bound are altered by the vacuum polarization. 相似文献
992.
It is found from Maxwell’s equations that the magnetic field lines are good analogues of relativistic strings. The Lorentz force per unit length of magnetic tube is interpretable as Magnus force acting on each individual magnetic tube. It is shown that the superconducting current in pulsar’s interior causes local rotation of magnetic flux tubes carrying quantized flux. Such local rotation remains operative as long as the induced magnetic field of normal electron fluid is above the lower critical field but below the upper. The conservation of magnetic flux leads to a geometrical condition in the form of the Weingarten identity which ensures the existence of family of “magnetic world sheetrdquo;. Each “magnetic world sheet” is a magnetic flux conserving surface. In the process of collapse, a compact spacelike cross-section of a magnetic tube terminates into a trapped surface if the magnetic energy grows faster along the fluid flow lines than that along the magnetic field lines. 相似文献
993.
Influence of hydrostatic pressure and temperature on electronic band parameters for zinc-blende AlxGa1–xAs was investigated by means of pseudopotential calculations. The agreement between our results and the available experimental data is generally satisfactory. Our results showed that the effect of pressure leads to a decrease of the crossing point and the optical bowing parameter. However, the temperature effect was found to be insignificant on both crossing point and bowing parameter. 相似文献
994.
Considering the SM Higgs boson mass in the range of (95–235) GeV, we present here a mechanism for indirect searches of this scalar in UHE cosmic rays interactions. The mechanism is the decay of Higgs bosons which are produced through bubble formation due to vacuum excitation in an UHE cosmic rays interactions with air nuclei. We develop a model of hadronic interaction based on algorithms of the GENCL code of the UA5 experiment of CERN and some physics of CORSIKA code (Karlsruhe report), incorporating a fraction of energy transfer to bubble formation through vacuum excitation and subsequent multiparticle production via conversion of Higgs boson to heavy fermion pairs. Such events are expected to have high multiplicity and excess muons. This mechanism has significant effect starting from E
P 1018eV. It is found that the average muon number decreases gradually upto 175 GeV Higgs boson mass and remain practically constant thereafter for all primary energies (E
P) above 1018 eV and for all fractions of energy transfer (f
e 0.01–0.5). The fluctuation of muon multiplicity decreases with E
P and increases very slowly with Higgs mass upto 175 GeV, remaining practically invariant thereafter. 相似文献
995.
Lorenzo?BertiniEmail author Emilio N.M.?Cirillo Enzo?Olivieri 《Communications in Mathematical Physics》2005,258(2):405-443
In this paper we develop a general theory which provides a unified treatment of two apparently different problems. The weak Gibbs property of measures arising from the application of Renormalization Group maps and the mixing properties of disordered lattice systems in the Griffiths’ phase. We suppose that the system satisfies a mixing condition in a subset of the lattice whose complement is sparse enough namely, large regions are widely separated. We then show how it is possible to construct a convergent multi-scale cluster expansion.The authors acknowledge the support of Cofinanziamento MIUR. 相似文献
996.
The empirical validity of the locality (LOC) principle of relativity is used to argue in favour of a local hidden variable theory (HVT) for individual quantum processes. It is shown that such a HVT may reproduce the statistical predictions of quantum mechanics (QM), provided the reproducibility of initial hidden variable states is limited. This means that in a HVT limits should be set to the validity of the notion of counterfactual definiteness (CFD). This is supported by the empirical evidence that past, present, and future are basically distinct. Our argumentation is contrasted with a recent one by Stapp resulting in the opposite conclusion, i.e. nonlocality or the existence of faster-than-light influences. We argue that Stapps argumentation still depends in an implicit, but crucial, way on both the notions of hidden variables and of CFD. In addition, some implications of our results for the debate between Bohr and Einstein, Podolsky and Rosen are discussed. 相似文献
997.
In a recent paper, a “distance” function,
, was defined which measures the distance between pure classical and quantum systems. In this work, we present a new definition of a “distance”, D, which measures the distance between either pure or impure classical and quantum states. We also compare the new distance formula with the previous formula, when the latter is applicable. To illustrate these distances, we have used 2 × 2 matrix examples and two-dimensional vectors for simplicity and clarity. Several specific examples are calculated. 相似文献
998.
Taking the view that computation is after all physical, we argue that physics, particularly quantum physics, could help extend
the notion of computability. Here, we list the important and unique features of quantum mechanics and then outline a quantum
mechanical “algorithm” for one of the insoluble problems of mathematics, the Hilbert's tenth and equivalently the Turing halting
problem. The key element of this algorithm is the computability and measurability of both the values of physical observables and of the quantum-mechanical probability distributions for these values. 相似文献
999.
Two approaches toward the arrow of time for scattering processes have been proposed in rigged Hilbert space quantum mechanics.
One, due to Arno Bohm, involves preparations and registrations in laboratory operations and results in two semigroups oriented
in the forward direction of time. The other, employed by the Brussels-Austin group, is more general, involving excitations
and de-excitations of systems, and apparently results in two semigroups oriented in opposite directions of time. It turns
out that these two time arrows can be related to each other via Wigner's extensions of the spacetime symmetry group. Furthermore,
their are subtle differences in causality as well as the possibilities for the existence and creation of time-reversed states
depending on which time arrow is chosen. 相似文献
1000.
F.?RahamanEmail author B.?C.?Bhui M.?Kalam 《International Journal of Theoretical Physics》2005,44(9):1413-1418
We analyze the space-time structure of local gauge string with a phenomenological energy–momentum tensor, as prescribed by
Vilenkin, in an arbitrary number of space-time dimensions with a non-zero cosmological constant Λ. A set of solutions of the
full non-linear Einstein's equations for the interior region of such a string is presented. 相似文献