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1.
The quantum harmonic oscillator is described in terms of two basic sets of coordinates: linear coordinates x, px and angular coordinates ei, P (action-angle variables). The angular coordinate ei is assumed unitary, the conjugate momentum p is assumed Hermitian, and ei and p are assumed to be a canonical pair. Two transformations are defined connecting the angular coordinates to the linear coordinates. It is found that x, px can be physical, i.e., Hermitian and canonical, only under constraints on the p eigenvalue spectrum. The conclusion is that ei can be a unitary operator. A parallel analysis of the classical harmonic oscillator is done with equivalent results.  相似文献   

2.
The continuum form of the Gauss-Hertz principle is extended to include the time domain as well as space. The Schrödinger equation and general relativity are derived by this method. The equivalence of the principle is shown to that of the Hamiltonian method where the energy is the expression –[ 2 +A·2 A], with being the difference between the acceleration potential and potential energy density, andA being the difference between the vector potentials of the acceleration field and the force field. The goal of Hertz to demonstrate a third arrangement of the principles of mechanics...which starts with... time, space and mass has apparently been achieved for relativity and for quantum mechanics, in addition to those classical equations previously found.  相似文献   

3.
A variety of rigorous inequalities for critical exponents is proved. Most notable is the low-temperature Josephson inequalitydv +2 2–. Others are 1 1 +v, 1 1 , 1,d 1 + 1/ (for d),dv, 3 + (for d), 4 , and 2m 2m+2 (form 2). The hypotheses vary; all inequalities are true for the spin-1/2 Ising model with nearest-neighbor ferromagnetic pair interactions.NSF Predoctoral Fellow (1976–1979). Research supported in part by NSF Grant PHY 78-23952.  相似文献   

4.
We study resistor diode percolation at the transition from the non-percolating to the directed percolating phase. We derive a field theoretic Hamiltonian which describes not only geometric aspects of directed percolation clusters but also their electric transport properties. By employing renormalization group methods we determine the average two-port resistance of critical clusters, which is governed by a resistance exponent . We calculate to two-loop order.  相似文献   

5.
Scale invariance is considered in the context of gravitational theories where the action, in the first order formalism, is of the form S= L 1 d 4 x+ L 2 d 4 x where the volume element d 4 x is independent of the metric. For global scale invariance, a dilaton has to be introduced, with non-trivial potentials V()=f 1 e in L 1 and U()=f 2 e 2 in L 2 . This leads to non-trivial mass generation and a potential for which is interesting for inflation. Interpolating models for natural transition from inflation to a slowly accelerated universe at late times appear naturally. This is also achieved for Quintessential models, which are scale invariant but formulated with the use of volume element d 4 x alone. For closed strings and branes (including the supersymmetric cases), the modified measure formulation is possible and does not require the introduction of a particular scale (the string or brane tension) from the begining but rather these appear as integration constants.  相似文献   

6.
We investigate the statistical and dimensional properties of uniform star polymers attached by the branching vertex of degreef in a wedge geometry in three dimensions and described by the wedge angles and. We show that the growth constant is equal to f , where is the self-avoiding walk limit. Thef and (, ) dependences of the corresponding critical exponent f (, ) are studied using Monte Carlo techniques. In the casef=1, our results are compared with existing predictions obtained from series expansion and renormalization group methods. We have also estimated the amplitudes for the mean square radius of gyration and the mean square end-to-end branch length. Our results for the ratio of the mean square radius of gyration of anf-star to that of a linear polymer of the same degree of polymerization attached in a similar wedge, and the analogous ratio for the mean square end-to-end branch length, are consistent with these ratios being lattice-independent quantities.  相似文献   

7.
It is shown that if the Brans-Dicke equations have the solution,g ij generated by the trace free sourceT n (T-O) then there exists an adjoint solution –1, 2gij of these equations generated by the source -2 T u. An example is considered.  相似文献   

8.
We consider two dimensional boson field theories with an interaction potentialV (). We show how to define a cut-off, renormalised Hamiltonian for a certain class of non-polynomialV (), which are defined via an integral transform. We formulate precisely a variational argument devised by Coleman, obtaining a constraint on the coupling constant of the theory with generalV (), and illustrate the argument with several examples.  相似文献   

9.
Consider a viscous incompressible fluid in the half-plane and letu t be a solution of the Navier-Stokes equation. In this paper we prove that the product formula (E t/n G t/n u) n u 0, whereE t is the Euler flow,G t is the heat flow and is a suitable operator describing the vorticity production due to the boundary, converges uniformly tou t in the limitn .Research supported by Ministero della Pubblica Istruzione, CNR contract No. 84.00016.02 and GNFM  相似文献   

10.
The renormalization group technique is used to study rigorously the ()4 perturbation of the massless lattice field in dimensionsd2. Asymptoticity of the perturbation expansion in powers of is established for the free energy density. This is achieved by using Kadanoff's block spin transformation successively to integrate out high momentum degrees of freedom and by applying ideas previously used by Gallavotti and Balaban in the context of the ultraviolet problems. The method works for arbitrary semibounded polynomials in and .Supported in part by the National Science Foundation under Grant No. PHY 79-16812On leave from Department of Mathematical Methods of Physics, University, PL-00-682 Warsaw, Poland  相似文献   

11.
No Heading The interplay between the tracial property and minimality of dispersions of states on projections of von Neumann algebras and C*-algebras is investigated. Let be a state on a C*-algebra A with the projection structure P(A). The dispersion () is defined as () = sup{(p) – (p)2 | p P(A)}. It is proved that () 2/9 whenever is a state on a real rank zero C*-algebra with no nonzero abelian representation. New characterization of traces in terms of dispersions is proved: A state on a von Neumann algebra without abelian and Type I2 direct summands is a trace if and only if has the minimal dispersion on all 3x3 matrix substructures. A similar characterization of semifinite normal traces on von Neumann algebras is obtained. The connection between unitary invariance of states and minimal dispersion property on C*-algebras is studied. Besides providing a new characterization of trace in terms of physically relevant properties, the existing results on hidden variables in W*- and C*-formalism of quantum mechanics are strengthen.  相似文献   

12.
Under weak technical assumptions on a net of local von Neumann algebras {A(O)} in a Hilbert space , which are fulfilled by any net associated to a quantum field satisfying the standard axioms, it is shown that for every vector state in there exist observables localized in complementary wedge-shaped regions in Minkowski space-time that maximally violate Bell's inequalities in the state . If, in addition, the algebras corresponding to wedge-shaped regions are injective (which is known to be true in many examples), then the maximal violation occurs in any state on () given by a density matrix.  相似文献   

13.
The newly proposed anisotropic fiber structures with cylindrical polar principal axes appear to be an interesting novel class of special lightguides. In this paper, some interesting results relating to such fibers are derived which, to the knowledge of this author, have not yet been reported in the literature. It is found that, ifn c0 ( )1/2>n zc0( r )1/2, TE01 will be the fundament mode with a range of single-mode operation given by 2.61n zc0 (2 r )1/2 /a<2.61n c0(2 )1/2. On the other hand, ifn zc0 ( r )1/2>n c0( )1/2, then TM01 becomes the fundamental mode whose single-mode operation range is 2.61n c0 (2 )1/2 /a<2.61n zc0(2 r )1/2.  相似文献   

14.
The k theory is compared with the multilinear theory of scalar fields 1, 2, ..., k having the same mass as that of . In particular, it is shown that Feynman integrals encountered in the 3 theory are not necessarily present also in the 1 2 3 theory, but they are if they correspond to planar Feynman graphs having no tadpole part. Furthermore, a necessary and sufficient condition for the presence of a 3 Feynman integral in the 1 2 2 theory is found. Those considerations are applications of graph theory, especially of the coloring problem of graphs, to Feynman graphs.  相似文献   

15.
Consider a gauge fieldF and a scalar field with a self-couplingV() as well as the standard coupling betweenF and . If 02V()·V(), there are no classical lumps. IfV()=||4 the system is conformally invariant and all the energy radiates out along the light cone.Research supported in part by NSF grants MCS 77-01340 and MCS 78-03567  相似文献   

16.
In this paper we propose a new theory of a fiber bundle provided with a local metric of internal space. The fibers differ from usual fibers, having an enlarged factor. The enlargement may be procured by a differential mapping(x) from structure groupG to the fiberF x atx M, and(x)R. The torsion presented stems from the local metric of internal space and the local metric stems from a induced mapping *(x) of(x). From the theory we can get the Brans-Dicke theory with torsion. If we assume the spin density of the gauge field determines the enlarged factor of the fiberF x, our theory is an extended Cartan theory.  相似文献   

17.
We have investigated the effect of inter-particle repulsion and particle–substrate interaction on the microstructure of silica particle monolayer films fabricated by an evaporation-induced self-assembly method as a function of surface coverage. Suspensions of mono-dispersed colloidal silica particles (106 nm diameter) without binders cast on PET substrates by bar coating were evaporated under a fixed condition to give two-dimensional particle films. The inter-particle repulsion was controlled by zeta potential of the particle suspensions. The particle–substrate interaction was varied by the surface treatment of the substrates by argon radio frequency plasma. The self-assembled microstructure was observed by atomic force microscopy (AFM) and quantitatively evaluated by Voronoi analysis in terms of particle order and domain quality. In all the conditions attempted, the microstructure improved with the increase of surface coverage (C). However, little difference in the correlation between C and the microstructure due to the experimental conditions was observed until C reached about 0.6, where both particle order and domain quality of more inter-particle repulsion (higher absolute value of zeta potential) began to exceed those of less inter-particle repulsion only when the substrates with less particle–substrate attraction (substrates with no surface treatment) were used. These results were consistent with the AFM observation. By considering a feasible model for the process, it could be inferred that the microstructure dependence on the inter-particle repulsion originated from a leap in the frequency of inter-particle collision at a critical value of C (=49/750.65 in the model). We found that stronger inter-particle repulsion and weaker particle–substrate attraction were preferable for the better microstructure above the critical C of about 0.6.  相似文献   

18.
We demonstrate with the example of Cahn-Hilliard dynamics that the macroscopic kinetics of first-order phase transitions exhibits an infinite number of constants of motion. Moreover, this result holds in any space dimension for a broad class of nonequilibrium processes whose macroscopic behavior is governed by equations of the form /t = W(), where is an order parameter,W is an arbitrary function of , and is a linear Hermitian operator. We speculate on the implications of this result.  相似文献   

19.
A Higgs vacuum field is characterized by the set of conditionsD =0, which lead to a generalized Meissner effect and partially determine the vector potentialA in terms of . Applying this method to the Weinberg-Salam theory, we assert that there exist stringlike configurations in which a pair of magnetic poles are bound by a flux string of theZ 0 field, with an energy scale in the TeV range. We also point out that pure gauges in non-Abelian gauge theories are not well-defined due to topological singularities. In order to be meaningful, they must be enlarged to a class of almost pure gauges which include the various known topological configurations.Work supported in part by the U.S. Department of Energy, San Francisco Office, and by the Sherman Fairchild Distinguished Scholars Program.On leave from the University of Chicago.  相似文献   

20.
In this paper we have obtained the general vacuum solution for Bianchi type V in the Brans-Dicke theory. It is shown that for the special case=0, the sourceless scalar field is dynamically an essential factor which determines the cosmological expansion parametersR i and the singularity does not occur whent=0. For this solution there is no antigravity (>0), which disagrees with other solutionsa for BDT-Bianchi type V  相似文献   

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