共查询到20条相似文献,搜索用时 15 毫秒
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Quantum measurement problem has existed many years and inspired a large of literature in both physics and philosophy, but there is still no conclusion and consensus on it. We show it can be subsumed into the quantum theory if we extend the Feynman path integral by considering the relativistic effect of Feynman paths. According to this extended theory, we deduce not only the Klein--Gordon equation, but also the wave-function-collapse equation. It is shown that the stochastic and instantaneous collapse of the quantum measurement is due to the “potential noise” of the apparatus or environment and “inner correlation” of wave function respectively. Therefore, the definite-status of the macroscopic matter is due to itself and this does not disobey the quantum mechanics. This work will give a new recognition for the measurement problem. 相似文献
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Using bosonization techniques for (2+1) D systems, we show that the transverse conductance for a system with general current interactions, when measured between perfect Hall regions is not renormalized at low temperatures. Our method extends two results we have recently obtained on low dimensional fermionic systems: on the one hand, the relationship between universality of Landauer conductance and universality of bosonization rules for (1+1) D systems, and on the other hand, the universal character of the bosonized topological current associated to a (2+1) D fermionic system with current interactions. 相似文献
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S. I. Muslih 《General Relativity and Gravitation》2002,34(7):1059-1065
The connection between the canonical and the path integral formulations of Einstein's gravitational field is discussed using the Hamilton Jacobi method. Unlike conventional methods, its shown that our path integral method leads to obtain the measure of integration with no -functions, no need to fix any gauge and so no ambiguous determinants will appear. 相似文献
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Herbert W. Hamber 《General Relativity and Gravitation》2009,41(4):817-876
I review the lattice approach to quantum gravity, and how it relates to the non-trivial ultraviolet fixed point scenario of
the continuum theory. After a brief introduction covering the general problem of ultraviolet divergences in gravity and other
non-renormalizable theories, I discuss the general methods and goals of the lattice approach. An underlying theme is the attempt
at establishing connections between the continuum renormalization group results, which are mainly based on diagrammatic perturbation
theory, and the recent lattice results, which apply to the strong gravity regime and are inherently non-perturbative. A second
theme in this review is the ever-present natural correspondence between infrared methods of strongly coupled non-abelian gauge
theories on the one hand, and the low energy approach to quantum gravity based on the renormalization group and universality
of critical behavior on the other. Towards the end of the review I discuss possible observational consequences of path integral
quantum gravity, as derived from the non-trivial ultraviolet fixed point scenario. I argue that the theoretical framework
naturally leads to considering a weakly scale-dependent Newton’s constant, with a scaling violation parameter related to the
observed scaled cosmological constant (and not, as naively expected, to the Planck length).
Invited lecture presented at the conference “Quantum Gravity: Challenges and Perspectives”, Bad Honnef, 14–16 April 2008.
To appear in the proceedings edited by Hermann Nicolai. 相似文献
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In the framework of causal perturbation theory we analyze the gauge structure of a massless self-interacting quantum tensor field. We look at this theory from a pure field theoretical point of view without assuming any geometrical aspect from general relativity. To first order in the perturbation expansion of the S-matrix we derive necessary and sufficient conditions for such a theory to be gauge invariant, by which we mean that the gauge variation of the self-coupling with respect to the gauge charge operator Q is a divergence in the sense of vector analysis. The most general trilinear self-coupling of the graviton field turns out to be the one derived from the Einstein–Hilbert action plus divergences and coboundaries. 相似文献
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针对近垒能量下经典涨落耗散模型预期的重核熔合几率比实验结果偏小的问题, 发展了一种实时间路径积分方法并用于研究重核熔合激发函数, 给出了包含量子涨落效应的解析表达式。 计算了几个对称和近似对称反应系统的熔合几率, 结果表明理论结果与实验值符合较好。 还讨论了颈部增长对熔合障碍的影响。 A real time path integral approach is developed in order to work out a correct solution to a problem for the smaller result of the fusion probability of heavy nuclei based on the classical diffusion model at sub barrier energies. An analytical expression for the quantum fusion probability is proposed,which contains the quantum fluctuation effect. The fusion probabilities of several symmetrical and approximate symmetrical systems are calculated, the heoretical results are in agreement with the experimental data. The influence of the neck length and its fluctuation upon the fusion hindrance is discussed. 相似文献
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A rigorous path integral construction for a wide class of Weyl evolution operators is based on a pseudo-differential -calculus on flat phase spaces of finite and infinite dimensions. 相似文献
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A novel path integral Monte Carlo (PIMC) approach for correlated many‐particle systems with arbitrary pair interaction in continuous space at low temperatures is presented. It is based on a representation of the N ‐particle density operator in a basis of (anti‐)symmetrized N ‐particle states (configurations of occupation numbers). The path integral is transformed into a sum over trajectories with the same topology and, finally, the limit of M → ∞, where M is the number of high‐temperature factors, is analytically performed. This yields exact expressions for the thermodynamic quantities and allows to perform efficient simulations for fermions at low temperature and weak to moderate coupling. Our method is expected to be applicable to dense quantum plasmas in the regime of strong degeneracy where conventional PIMC fails due to the fermion sign problem (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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In this paper we shall address this problem: Is quantum gravity constraints algebra closed and what are the quantum Einstein’s
equations. We shall investigate this problem in the de-Broglie-Bohm quantum theory framework. It is shown that the constraint
algebra is weakly closed and the quantum Einstein’s equations are derived. 相似文献
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We summarize the twelve most important in our view novel concepts that have arisen, based on results that have been obtained,
from various applications of Abstract Differential Geometry (ADG) to Quantum Gravity (QG). The present document may be used
as a concise, yet informal, discursive and peripatetic conceptual guide-cum-terminological glossary to the voluminous technical research literature on the subject. In a bonus section at the end, we
dwell on the significance of introducing new conceptual terminology in future QG research by means of ‘poetic language’. 相似文献
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Akira InomataGeorg Junker 《Physics letters. A》2012,376(4):305-308
Quantum mechanics in conical space is studied by the path integral method. It is shown that the curvature effect gives rise to an effective potential in the radial path integral. It is further shown that the radial path integral in conical space can be reduced to a form identical with that in flat space when the discrete angular momentum of each partial wave is replaced by a specific non-integral angular momentum. The effective potential is found proportional to the squared mean curvature of the conical surface embedded in Euclidean space. The path integral calculation is compatible with the Schrödinger equation modified with the Gaussian and the mean curvature. 相似文献
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The probability representation for quantum states of the universe in which the states are described by a fair probability
distribution instead of wave function (or density matrix) is developed to consider cosmological dynamics. The evolution of
the universe state is described by standard positive transition probability (tomographic transition probability) instead of
the complex transition probability amplitude (Feynman path integral) of the standard approach. The latter one is expressed
in terms of the tomographic transition probability. Examples of minisuperspaces in the framework of the suggested approach
are presented. Possibility of observational applications of the universe tomographs are discussed. 相似文献
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James B. Hartle 《International Journal of Theoretical Physics》2006,45(8):1390-1396
Familiar quantum mechanics assumes a fixed spacetime geometry. Quantummechanics must therefore be generalized for quantum gravity where spacetime geometry is not fixed but rather a quantum variable. This extended abstract sketches a fully fourdimensional generalized quantum mechnics of cosmological spacetime geometries that is one such generalization.This contribution to the proceedings of the Glafka Conference is an extended abstract of the author's talk there. More details can be found in the references cited at the end of the abstract expecially (Hartle, 1995). 相似文献
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An isomorphism between fully quantized fermion and boson fluids and classical polymer mixtures is used as a point of departure to initiate an analytic treatment of quantum fluids. 相似文献
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In this paper, we study the phase diagram of a frustrated spin ladder model by applying the bosonization technique and the density-matrix renormalization-group (DMRG) algorithm. Effect of the intra-chain next-nearest-neighbor (NNN) super-exchange interaction is investigated in detail and the order parameters are calculated to detect the emergence of the dimerized phases. We find that the intra-chain NNN interaction plays a key role in inducing dimerized phases. 相似文献