首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
Typed Quantum Logic   总被引:1,自引:0,他引:1  
The aim of this paper was to lift traditional quantum logic to its higher order version with the help of a type-theoretic method. A higher order axiomatic system is defined explicitly and then a sound and complete class of models is given. This is an attempt to provide a quantum counterpart of classical set theory or intuitionistic topos.  相似文献   

2.
I sketch a self-contained framework for quantum mechanics based on its path-integral or sum-over-histories formulation. The framework is very close to that for classical stochastic processes like Brownian motion, and its interpretation requires neither measurement nor state-vector as a basic notion. The rules for forming probabilities are nonclassical in two ways: they use complex amplitudes, and they (apparently unavoidably) require one to truncate the histories at a collapse time, which can be chosen arbitrarily far into the future. Adapting this framework to gravity yields a formulation of quantum gravity with a fully spacetime character, thereby overcoming the frozen nature of the canonical formalism. Within the proposed adaptation, the value of the collapse time is identified with total elapsed spacetime four-volume. Interestingly, this turns the cosmological constant into an essentially classical constant of integration, removing the need for microscopic fine tuning to obtain an experimentally viable value for it. Some implications of the V = T rule for quantum cosmology are also discussed.  相似文献   

3.
I consider various experiments related to the so-called macroscopic quantum coherence experiment, which are probably at present in the class of thought experiment but are likely to become realistic in the next few decades. I explore the way in which outcomes consistent with the predictions of quantum mechanics would be interpreted by an adherent of, respectively, the Copenhagen, statistical, and Bohmian interpretations of the formalism.  相似文献   

4.
The notion of probability is generalized to that of likelihood, and a natural logical structure is shown to exist for any physical theory which predicts likelihoods. Two physically based axioms are given for this logicai structure to form an orthomodular poset, with an order-determining set of states. The results strengthen the basis of the quantum logic approach to axiomatic quantum theory.  相似文献   

5.
The concept of abacus logic has recently been developed by the author (Malhas, n.d.). In this paper the relation of abacus logic to the concept of fuzziness is explored. It is shown that if a certain regularity condition is met, concepts from fuzzy set theory arise naturally within abacus logics. In particular it is shown that every abacus logic then has a pre-Zadeh orthocomplementation. It is also shown that it is then possible to associate a fuzzy set with every proposition of abacus logic and that the collection of all such sets satisfies natural conditions expected in systems of fuzzy logic. Finally, the relevance to quantum mechanics is discussed.  相似文献   

6.
On the basis of Mackey's axiomatic approach to quantum physics or, equivalently, of a state-event-probability (SEVP) structure, using a quite standard fuzzification procedure, a set of unsharp events (or effects) is constructed and the corresponding state-effect-probability (SEFP) structure is introduced. The introduction of some suitable axioms gives rise to a partially ordered structure of quantum Brouwer-Zadeh (BZ) poset; i.e., a poset endowed with two nonusual orthocomplementation mappings, a fuzzy-like orthocomplementation, and an intuitionistic-like orthocomplementation, whose set of sharp elements is an orthomodular complete lattice. As customary, by these orthocomplementations the two modal-like necessity and possibility operators are introduced, and it is shown that Ludwig's and Jauch-Piron's approaches to quantum physics are interpreted in complete SEFP. As a marginal result, a standard procedure to construct a lot of unsharp realizations starting from any sharp realization of a fixed observable is given, and the relationship among sharp and corresponding unsharp realizations is studied.  相似文献   

7.
The Dirac spinors and matrices are used in combination with the Arnowitt-Deser-Misner formalism in order to obtain yet another formulation of Hamiltonian general relativity, together with a new form of the Gauss-Codazzi equations. The relation with Ashtekar's variables is analyzed; it is shown, for instance, that the matrices are equivalent to the electric field variable. The electric and magnetic decomposition of the gravitational field is also studie using Dirac matrices.  相似文献   

8.
The ac resistivity of a 110 K phase multiphase polycrystalline Ca-Sr-Bi-Cu-O compound and an 85 K phase single-crystalline Ca0.9Sr2.1Cu2.0O8 + has been measured in various magnetic fields up to 8 T. Values forB c 2/ (0) of 71.5 T and forB c2 (0) of 542 T are found for the 85 K phase sample. A value forB c2(0) of 57.9 T is estimated for the 110K phase compound.  相似文献   

9.
A propositional calculus for quantum mechanical systems is presented which formalizes sequential connectives and then and or then for yes-no experiments in the framework of complex Hilbert space. Properties of these connectives are compared with some well-known lattice-theoretical results in quantum logic. Probabilities and objectivization versus the Copenhagen interpretation are discussed in connection with Young's two-slit experiment.  相似文献   

10.
, . . . , , . , . , . .
Betatron oscillations in an accelerator with a general field I
The paper gives a linear theory of equilibrium trajectories in an accelerator with a generalized magnetostatic field, the components of which are defined on a general rotation surface. Equations of motion of the particles in natural coordinates are derived with respect to the change in energy and dissipative force. A system of equilibrium trajectories is found in the general form. Conditions for the field components on the reference surface, necessary for the existence of equilibrium trajectories, for the conservation of their geometric similarities and for maintaining the constancy of the frequencies of the betatron oscillations, are derived. A condition is also derived which must be satisfied by the reference surface in order to conserve constant circular frequency of the particles. It is seen that it is not possible to find a field for an accelerator with an exactly constant circular frequency and with constant frequencies of the betatron oscillation in the relativistic energy region. An ultra-relativistic cyclotron with such properties is realizable.
  相似文献   

11.
Quantum Logic as a Basis for Computations   总被引:1,自引:0,他引:1  
It is shown that computations can be founded on the laws of the genuine(Birkhoff—nvon Neumann) quantum logic treated as a particular version ofukasiewicz infinite-valued logic. A new way of encoding nonexact data whichencodes both the value of a number and its fuzziness is introduced. A simpleexample of a full adder that works in the proposed way is given and it is comparedwith other designs of quantum adders existing in the literature. A controversybetween the meaning of the very term quantum logic as used recently withinthe theory of quantum computations and the traditional meaning of this term isbriefly discussed.  相似文献   

12.
We analyze a chain of nonlinear oscillators and calculate transport quantities relevant to the propagation of vibrational excitations in the chain. We obtain explicit expressions for oscillator displacements as well as for the mean-square-displacements of the vibrational excitation for several different initial conditions including a localized and a grating initial condition, and study with their help the effects of nonlinearity on vibrational propagation.  相似文献   

13.
- , Li(, ) ( =17,6. 14,8 MeV). , u . , gQ=0,74+-0,16 MeV 58Fe E * : 6,76; 6,44; 5,90; 5,47; 4,98; 4,35; 3,50; 3,20 MeV. , .  相似文献   

14.
All gauge theories need somethingfixed even as something changes.Underlying the implementation of these ideas all majorphysical theories make indispensable use of anelaborately designed spacetime model as the something fixed,i.e., absolute. This model must provide at least thefollowing sequence of structures: point set, topologicalspace, smooth manifold, geometric manifold, base forvarious bundles. The fine structure ofspacetime inherent in this sequence is of courseempirically unobservable directly, certainly whenquantum mechanics is taken into account. This issue isat the basis of the difficulties in quantizing generalrelativity and has been approached in many differentways. Here we review an approach taking into account thenon-Boolean properties of quantum logic when forming a spacetime model. Finally, we recall how thefundamental gauge of diffeomorphisms (the issue ofgeneral covariance vs. coordinate conditions) raiseddeep conceptual problems for Einstein in his earlydevelopment of general relativity. This is clearlyillustrated in the notorious holeargument. This scenario, which does not seem to bewidely known to practicing relativists, is neverthelessstill interesting in terms of its impact for fundamental gaugeissues.  相似文献   

15.
We investigate the Finkelstein-Misner geons for a non-simply-connected space-time manifold (M, g 0). We use relations between different Lorentzian structures unequivalent tog 0 and topological properties ofM given by the Morse theory. It implies that to some pieces of geons we have to associate Wheeler's worm-holes. Geons that correspond to time-orientable Lorentz structures are related tog 0 by Morse functions that describe the attaching of a handle of index one. In the case of geons associated to time-nonorientable Lorentzian structures, appropriate handles are related to loops along which the notion of time reverses. If we assume electromagnetic properties of geons, then only four species, v, e, p, m, of different geons can exist and geon m has to decay according to mv+p+e.  相似文献   

16.
We introduce an explicit definition for hidden correlations on individual entities in a compound system: when one individual entity is measured, this induces a well-defined transition of the proper state of the other individual entities. We prove that every compound quantum system described in the tensor product of a finite number of Hilbert spaces can be uniquely represented as a collection of individual entities between which there exist such hidden correlations. We investigate the significance of these hidden correlation representations within Aerts' creation-discovery approach and in particular their compatibility with the hidden measurement formalism. This leads us to the introduction of the notions of soft and hard acts of creation and to the observation that our approach can be seen as a theory of individuals when it is compared to the standard quantum theory.  相似文献   

17.
The effectiveness of a multicycle wavefront-inversion (WFI) algorithm in the problem of laser-radiation focusing in a randomly inhomogeneous medium is evaluated. Both local (for a single cycle) and integral (for the entire observation period) effectiveness criteria are examined. The dependence of these criteria on the main parameters of an adaptive system with WFI are determined. It is shown, in particular, that the WFI system must be adjusted for local conditions to increase the effectiveness of WFI of a noisy signal.Scientific-Industrial Organization Astrophysics. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 35, No. 8, pp. 702–714, August, 1992.  相似文献   

18.
19.
This article develops the postulate that spacetime-charge inversion invariance reflects a fundamental reciprocal symmetry in nature between the two long range forces, from which the derivation of Mach's principle (i.e., the principle that the fundamental parameters of the electromagnetically elementary charged particle are related to those describing the electromagnetically observable universe) follows quite easily. Interpreting this result, it is argued that relativity and quantum mechanics can be made conceptually compatible and mathematically consistent by this reciprocal symmetry if one realizes that relativity isboth a macroscopic, semiclassical theory (i.e., the global half of relativity, described by Eq. (1.1), including special and general relativity) and a microscopic theory (i.e., the local half of relativity, described by Eq. (2.1), including relativistic quantum mechanics and field theory). The reciprocal symmetry of nature, then, promises unique (differential and/or integral) relationships between the coordinate variables of the observers of these tworeciprocally related theories, which implies unique, consistent numerical values for the scalar curvatureR, the massM, and the critical density for closure, c, of the observable universe [derived from the elementary particle parameters (i.e., the electron mass and Coulomb radius)]. With this symmetry we also postulate a plausible mechanism for spontaneous generation of matter from the ubiquitous (zero-mass ether) nothingness of the Dirac sea of filled negative energy states, and can consistently interpret both the positive and negative-energy state solutions of Dirac's equation for massive, spin-1/2 (i.e., fermion) particles and both the advanced and retarded potential solutions of electromagnetic field equations. It is pointed out that, with this interpretation of the advanced potential solutions from electromagnetic field theory, one can actuallyderive causality from electromagnetic theory.  相似文献   

20.
One of the most satisfactory pictures for spinning particles is the Barut-Zanghi (BZ) classical theory for the relativistic extended-like electron, that relates spin to zitterbewegung (zbw). The BZ motion equations constituted the starting point for recent works about spin and electron structure, co-authored by us, which adopted the Clifford algebra language. This language results to be actually suited for a hydrodynamical reformulation of the BZ theory. Working out a probabilistic fluid, we are allowed to reinterpret the original classical spinors as quantum wave-functions for the electron. We can pass to quantize the BZ theory: by employing this time the tensorial language, more popular in first-quantization. Quantizing the BZ theory, however, does notlead to the Dirac equation, but rather to a nonlinear, Dirac–like equation, which can be regarded as the actual quantum limit of the BZ classical theory. Moreover, a new variational approach to the BZ probabilistic fluid shows that it is a typical Weyssenhoff fluid, while the Hamilton-Jacobi equation (linking mass, spin,and zbw frequency together) appears to be nothing but a special case of the de Broglie energy–frequency relation. Finally, after having discussed the remarkable relation existing between the gauge transformation U(1) and ageneral rotation on the spin plane, we clarify and comment on the two-valuedeness nature of the fremionic wave-function, as well as on the parity and charge conjugation transformations.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号