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 62 毫秒
1.
2.
Recently Bell has conjectured that, with epsilonics, one should be able to argue, à la EPR, from almost ideal correlations (in parallel Bohm-Bell pair experiments) to almost determinism, and that this should suffice to derive an approximate Bell-type inequality. Here we prove that this is indeed the case. Such an inequality—in principle testable—is derived employing only weak locality conditions, imperfect correlation, and a propensity interpretation of certain conditional probabilities. Outcome-independence (Jarrett's completeness condition), hence factorability of joint probabilities, is not assumed, but rather an approximate form of this is derived. An alternative proof to the original one of Bell [1971] constraining stochastic, contextual hidden-variables theories is thus provided.  相似文献   

3.
A recent analysis by Richard Price of spherical collapse with small nonspherical perturbations is here generalized to the case of an electrically charged collapsing star (0¦Q¦-M). The perturbations are confined to a scalar field generated by a nonspherical distribution of scalar charge in the star. As in the electrically neutral case, the scalar perturbations are probably a prototype for all others — electromagnetic, gravitational, and higherspin. The collapse is shown to produce a Reissner-Nordström black hole, and the scalar-field perturbations are shown to radiate completely away; but they die out more slowly the larger is the star's electric charge. For charge ¦Q¦M, the -pole part of the perturbation at fixedr and late times is dominated by a tail that dies out ast –(2+ 2). But for ¦Q¦=M, the primary outgoing waves emitted from the star's surface are everywhere larger than the tail. At fixedr and late times they die as t–(+2). Also, a calculation of the redshift shows that a collapsing star becomes black more slowly the larger is the star's electric charge.Supported in part by the National Science Foundation (GP-27304, GP-28027, GP-19887).  相似文献   

4.
(GaSb), - 120–340 °K. : E2=(0,773–0,75.10–6 T 2) ., - .  相似文献   

5.
A cluster of two atoms described by thes-f model with Coulomb repulsion has been considered. The interaction between localized 4f electrons (S=1/2) is taken in the molecular field approximation. The thermodynamic quantities like magnetization, specific heat and correlation functions n , n , S z n , S z n , S z (n n ), n n and S + a + a as functions of temperature are presented for different band fillingN=0, 0.5, 1, 1.5, 2. The dependence of Curie temperature onN is calculated. The phase diagram forN=1 (T=0K) shows the possibility of existence of two phases: paramagnetic and ferromagnetic.The Curie temperature and the specific heat as functions ofN exhibit similar trends as found in experiments on doped magnetic semiconductors.  相似文献   

6.
A solution of the stress, deformation and deformation energy is given for an edge dislocation with its dislocation line having the shape of a circle in an unlimited isotropic medium. The possibility of using this solution in studying the dislocation loop in a crystal is discussed.
, . .


The author thanks M. imanová for carrying out the numerical calculations and J. Kaczér and B. esták for remarks and discussion.  相似文献   

7.
It is shown that if a fully atomic, complete orthomodular lattice satisfies a minimal support condition (m.s.c.), then it satisfies Piron's axioms, and is thereby shown to be the projection lattice of a generalized Hilbert space. It is shown, conversely, that m.s.c. holds in Hilbert space subspace lattices. The physical justification for m.s.c. is provided in the context of a property lattice (A, ) for a realistic entity (A, ) in the sense of Foulis-Piron-Randall. This context provides a clear focus on key issues in the debate over the appropriateness of requiring quantum logics to be represented over Hilbert spaces.  相似文献   

8.
Results of an experiment on the search for the emission of 0 mesons in neutron-induced fission of 235U nuclei based on the detection in coincidence of two -quanta from the 0-meson decay performed with the nuclear reactor developed at the Scientific-Research Nuclear Physics Institute at Tomsk Polytechnic University are described. The experimental setup comprised two erenkov spectrometers of total absorption for the detection and measurement of -quantum energy placed in two coaxial horizontal channels of the nuclear reactor. Water filters placed in the channels were used to protect the detectors from -, -, and neutron fluxes. To reject the cosmic radiation, scintillation counters of large area, operating in anticoincidence mode, were placed above each spectrometer. The experimentally measured limitation on the probability of neutral pion emission in neutron-induced fission of nuclei was established 4.1·10–11 with a 90% confidence level. The energy spectrum of -quanta from the active reactor zone was measured in the range 32–65 MeV. The parameters of the spectrum deviated from the results of theoretical calculations and from the experiment performed with the nuclear pulse reactor developed at the Joint Institute for Nuclear Research (Dubna).  相似文献   

9.
Nuclear emulsions were used to study the energy spectrum and forward-backward asymmetry of neutrons from the Co59(p,n) reaction forE p 6·5 MeV. It was found that the decay of the compound nucleus makes a maximum contribution of 50% to the reaction yield. Energies of some excited states of the Ni59 nucleus were also determined.
Co59(p,n) E p 6,5 MeV
- Co59(p,n) E p 6,5 MeV. , 50%. , Ni59.


The authors would like to thank all those who helped in this work, particularly all members of the cyclotron group of the Nuclear Research Institute of the Czechoslovak Academy of Sciences, who so willingly helped with the irradiation, and H. Koutová from the Faculty of Technical and Nuclear Physics, who carefully measured the emulsions. Our thanks are also due to R. Krejová from the Faculty of Technical and Nuclear Physics for developing the emulsions and J. Kopecký from the Nuclear Research Institute for providing the cobalt target.  相似文献   

10.
Quite often the compatibility of the EPR correlations with the relativity theory has been questioned; it has been stated that the first in time of two correlated measurements instantaneously collapses the other subsystem; it has been suggested that a causal asymmetry is built into the Feynman propagator. However, the EPR transition amplitude, as derived from the S matrix, is Lorentz andCPT invariant; the correlation formula is symmetric in the two measurements irrespective of their time ordering, so that the link of the correlations is the Feynman zigzag, and that causality isCPT invariant at the microlevel; finally, although the Feynman propagator has theP andCT symmetries, no causal asymmetry follows from that. As for Stapp's views concerning process and becoming, and his Whiteheadean concept of an advancing front, I object that they belong to factlike macrophysics, and are refuted at the microlevel by the EPR phenomenology, which displays direct Fokker-like space-time connections. The reason for this is a radical one. The very blending of a space-time picture and of a probability calculus is a paradox. The only adequate paradigm is one denying objectivity to space-time—but this, of course, is also required by the complementary of the x and the k pictures, which only look compatible at the macrolevel. Therefore, the classical objectivity must yield in favor of intersubjectivity. Only the macroscopic preparing and measuring devices have factlike objectivity; the transition of the quantal system takes place beyond both thex and thek 4-spaces. Then, the intrinsic symmetries between retarded and advanced waves, and statistical prediction and retrodiction, entails that the future has no less (but no more) existence than the past. It is the future that is significant in creative process, the elementary forms of which should be termed precognition or psychokinesis—respectively symmetric to the factlike taboos that we can neither know into the future nor act into the past. It is gratifying that Robert Jahn, at the Engineering School of Princeton University, is conducting (after others) conclusive experiments demonstrating low level psychokinesis—a phenomenon implied by the very symmetry of the negentropy-information transition. So, what pierces the veil of maya is the (rare) occurrence of paranormal phenomena. The essential severance between act and potentia is not a spacelike advancing front, but the out of and the into factlike space-time. Finally, I do not feel that an adequate understanding of the EPR phenomenology requires going beyond the present status of relativistic quantum mechanics. Rather, I believe that the potentialities of this formalism have not yet been fully exploited.  相似文献   

11.
Statics and dynamics of the modified kinetic discrete Gaussian model are treated selfconsistently using a Gaussian probability assumption. A non-trivial roughening temperatureT R is found in exactly two dimensions only. The free energyF, the correlation length and the interface roughness h 2 are found to behave—lnFlnh 2(T R T)–1 for temperaturesT approachingT R from below. The linear relaxation rate of the order parameter is found to be proportional to –2. As a model for crystal growth, the growth rate depends linearly upon the chemical potential difference aboveT R , shows a metastable regime belowT R with a spinodal limit of metastability c , beyond which oscillatory growth starts. The critical behavior of c is found to be ln c –(T R T)–1+O(ln (T R T)).  相似文献   

12.
A new expression e is obtained for resonance in the reaction e+e ar + with allowance for the radiative corrections, which also contain the emission of hard photons by the final leptons and the final value of the energy resolution E. An expression is obtained for the total probability of radiative lepton decay. A numerical analysis of the experimental data is made for the reaction +, and the parameters e+e (3, 1) e+e, and e 2 /, e, and are determined for (3, 1) resonance-with allowance for the radiative corrections.This paper was read (November 17–21, 1975) at a session on high-energy physics of the Department of Nuclear Physics of the Academy of Sciences of the USSR.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 29–34, March, 1977.  相似文献   

13.
We discuss stochastic Schrödinger operators and Jacobi matrices with wave functions, taking values in l so there are 2l Lyaponov exponents 1...l0 l+1...2l =–1. Our results include the fact that if 1=0 on a set positive measure, thenV is deterministic and one that says that {E|exactly 2j 's are zero} is the essential support of the a.c. spectrum of multiplicity 2j.Research partially supported by USNSF under grant DMS-8416049  相似文献   

14.
, . . . , , . , . , . .
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   

15.
16.
It is expected that quantum effects endow spacetime with stochastic properties near the Planck scale as exemplified by random fluctuations of the metric, usually referred to as spacetime foam or geometrodynamics. In this paper, a methodology is presented for incorporating Planck scale stochastic effects and corrections into general relativity within the ADM formalism, by coupling the Riemann 3-metric to white noise. The ADM—Cauchy evolution of a Riemann 3-metric h ij (t) induced on spacelike hypersurface C(t) can be interpreted within pure general relativity as a smooth geodesic flow in superspace, whose points consist of equivalence classes of 3-metrics. Coupling white noise to h ij gives Langevin stochastic differential equations for the Cauchy evolution of h ij, which is now a Brownian motion or diffusion in superspace. A fluctuation hij away from h ij is considered to be related to h ij by elements of the diffeomorphism group diff(C). Hydrodynamical Fokker—Planck continuity equations are formulated describing the stochastic Cauchy evolution of h ij as a probability flow. The Cauchy invariant or equilibrium solution gives a stationary probability distribution of fluctuations peaked around the deterministic metric. By selecting a physically viable ansatz for the scale dependent diffusion coefficient, one reproduces the Wheeler uncertainty relation for the metric fluctuations of quantum geometrodynamics. Treating h ij as a random variable, a non-linear Raychaudhuri—Langevin equation is derived describing the geometro-hydrodynamics of a congruence of fluid or dust matter propagating on the stochastic spacetime. For an initially converging congruence >0 at s the singularity =– at future proper time s=3/||$, which is expected in general relativity, is now smeared out near the Planck scale. Proper time s can be extended indefinitely (s) so that intrinsic metric fluctuations can restore geodesic completeness although the geodesics remain trapped for all time: although a singularity can be removed the collapsing matter still creates a black hole. A Fokker—Planck formulation also gives zero probability that – for s. Essentially, the short distance stochastic corrections to the deterministic equations of general relativity can remove pathologies such as singularities, conjugate points and geodesic incompleteness.  相似文献   

17.
18.
It is shown that the equation ,11 — ,22 = e — e-2 determines the intrinsic geometry of the two-dimensional affine sphere in the three-dimensional unimodular affine space like the sine-Gordon equation describes the metric on the surface of a constant negative curvature in the three-dimensional Euclidean space. The linear equations that determine the moving frame on the affine sphere are the Lax operators to the equation ,11 — ,22 = e — e-2.  相似文献   

19.
A fully micro realistic, propensity version of quantum theory is proposed, according to which fundamental physical entities—neither particles nor fields—have physical characteristics which determine probabilistically how they interact with one another (rather than with measuring instruments). The version of quantum smearon theory proposed here does not modify the equations of orthodox quantum theory: rather it gives a radically new interpretation to these equations. It is argued that (i) there are strong general reasons for preferrring quantum smearon theory to orthodox quantum theory; (ii) the proposed change in physical interpretation leads quantum smearon theory to make experimental predictions subtly different from those of orthodox quantum theory. Some possible crucial experiments are considered.  相似文献   

20.
A model explaining some observational properties of millisecond pulsars is presented in the framework of the general plasma model for pulsar emission developed by Al. Kazbegi, G. Machabeli, and G. Melikidze in a series of papers. In the region of the open magnetic field lines of the pulsar magnetosphere the existence of a relativistic electron-positron plasma penetrated by a primary particle beam is assumed. Wave excitation due to different plasma instabilities is considered. The main properties of pulsar radiation (e.g., existence of core and cone types of emission, circular polarization, subpulse drift phenomena, pulse nullings, and mode changing) are explained in the most natural way by this model. The observations show that despite the big difference between the physical parameters of the typical and millisecond pulsars their observed properties (pulse profiles, polarization, existence of two different modes in emission, frequency evolution, etc.) are more or less similiar and the physical mechanisms of their radiation do not differ fundamentally from each other. Some particular millisecond pulsars are considered based on the model presented, and predictions are made.Published from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 39, No. 3, pp. 343–351, March, 1996.We would like to thank Dr J. Gil for stimulating discussions. The research described in this publication was made possible in part by Grant RVI000 from the International Science Foundation.  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