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1.
We consider some orthomodular posets which are not lattices and the Gleason-type theorems for signed measures on them.  相似文献   

2.
Whereas there exists a mathematical proof for one-site breathers stability, and an unpublished one for two-site breathers, the methods for determining the stability properties of multibreathers rely on numerical computation of the Floquet multipliers or on the weak nonlinearity approximation leading to discrete nonlinear Schrödinger equations. Here we present a set of multibreather stability theorems (MST) that provides a simple method to determine multibreathers stability in Klein–Gordon systems. These theorems are based in the application of degenerate perturbation theory to Aubry’s band theory. We illustrate them with several examples.  相似文献   

3.
Level sets of Lorentzian distance functions with respect to a point and with respect to an achronal spacelike hypersurface, are analyzed. Some bounds for the Laplacian of such Lorentzian distance functions are obtained and, in relation to them, some spacetime singularity theorems are given.Supported by project BFM2001-3778-C03-01 (Spain).  相似文献   

4.
We establish two theorems for two time-delayed (chaotic) differential equation systems to achieve time-delayed generalized synchronization (TDGS). The theorems uncover general forms of two TDGS systems via a prescribed differentiable transformation. Based on the theorems, we use two-coupled Ikeda equations as the driving system to construct TDGS driven systems via two prescribed transformations. Numerical simulations demonstrate the effectiveness of the proposed theorems. It may be expected that our theorems provide new tools for understanding and studying TDGS phenomena.  相似文献   

5.
A time-harmonic plane dyadic electromagnetic field is scattered by a chiral body in a chiral environment. The body is either a perfect conductor or a dielectric. The incident field is a linear combination of left-circularly polarized and right-circularly polarized dyadic electromagnetic fields, each of which has a different wave number. We prove reciprocity and scattering theorems in dyadic form, which incorporate as special cases the corresponding known theorems for vector electromagnetic waves. Specializing to the same direction of incidence and observation in the general scattering theorems we obtain forward scattering theorems.  相似文献   

6.
范黎  梁灿彬 《物理学报》1989,38(7):170-176
本文推广了广义相对论的两个定理,把定理条件中的对称性减弱为共形对称性。推广后的定理为:1)Einstein方程的共形球对称电磁真空解必为Reissner-Nordstr?m解;2)Einstein方程的共形平面对称电磁真空解必为Kar解。 关键词:  相似文献   

7.
范黎  梁灿彬 《物理学报》1989,38(8):1384-1390
本文推广了广义相对论的两个定理, 把定理条件中的对称性减弱为共形对称性.推广后的定理为: l)Einstein 方程的共形球对称电磁真空解必为Reissoer-Nordsorom 解; 2 ))Einstein 方程的共形平面对称电磁真空解必为Kar 解. 关键词:  相似文献   

8.
The non-equilibrium free energy theorems show how distributions of work along non-equilibrium paths are related to free energy differences between the equilibrium states at the end points of these paths. In this paper we develop a natural way of barostatting a system and give the first deterministic derivation of the Crooks and Jarzynski relations for these isothermal isobaric systems. We illustrate these relations by applying them to molecular dynamics simulations of a model polymer undergoing stretching.  相似文献   

9.
The supersymmetric model in one dimension is used to calculate the fermion and scalar determinants in constant fields and express them in terms of the characteristic polynomials appearing in anomalies and index theorems. The operator determinants are transformed into those of a matrix.  相似文献   

10.
Starting from Onsager's assumption that the dynamical equilibrium correlations can be separated into a microscopic and a hydrodynamic part it is shown how to obtain phenomenological state variables in non-equilibrium, regression fluctuation theorems and (in some important cases) microscopic representations of thermal transport coefficients. The results are demonstrated for “pure” heat conduction, but most of them can be easily extended to systems which are described initially by the densities of dynamical constants.  相似文献   

11.
We present new classes of time operators of a Hamiltonian H (a self-adjoint operator) with discrete eigenvalues which may be degenerate. Moreover we formulate necessary and sufficient conditions for H to have time operators, determining the general form of them. As corollaries, non-existence theorems of time operators for some classes of H are derived.  相似文献   

12.
《Annals of Physics》1986,168(2):484-526
Two theorems are established which state that in certain circumstances the nth eigenvalue of one Schrödinger operator is higher or lower than the (n − 1)th eigenvalue of a second Schrödinger operator. One condition is the positivity of the difference of the two potentials and a certain behavior of this difference at the boundary. The other condition is in each theorem a differential inequality of the second order on one of the potentials. The proof involves a comparsion of the second logarithmic derivative of wave functions. By specifying the difference of the two potentials, specific forms of the theorems give new theorems on level spacings as well as old and new theorems on level ordering. A third theorem deals with perturbations of factorizable systems. Here explicit formulas connect the level splittings again with second order differential expressions of the perturbing potential.  相似文献   

13.
In the paper, we provide sufficient conditions for the oscillatory and asymptotic behavior of a new type of third-order nonlinear dynamic equations with mixed nonlinear neutral terms. Our theorems not only improve and extend existing theorems in the literature but also provide a new approach as far as the nonlinear neutral terms are concerned. The main results are illustrated by some particular examples.  相似文献   

14.
Laudisa (Found. Phys. 38:1110–1132, 2008) claims that experimental research on the class of non-local hidden-variable theories introduced by Leggett is misguided, because these theories are irrelevant for the foundations of quantum mechanics. I show that Laudisa’s arguments fail to establish the pessimistic conclusion he draws from them. In particular, it is not the case that Leggett-inspired research is based on a mistaken understanding of Bell’s theorem, nor that previous no-hidden-variable theorems already exclude Leggett’s models. Finally, I argue that the framework of Bohmian mechanics brings out the importance of Leggett tests, rather than proving their irrelevance, as Laudisa supposes.  相似文献   

15.
We single out an alternative, strict interpretation of the Einstein-Podolsky-Rosen criterion of reality, and identify the implied extensions of quantum correlations. Then we prove that the theorem of Bell, and the non-locality theorems without inequalities, fail if the new extensions are adopted. Therefore, these theorems can be interpreted as arguments against the wide interpretation of the criterion of reality rather than as a violation of locality.  相似文献   

16.
Conditions are analysed under which the statistics of soliton sectors of massive two-dimensional field theories can be properly defined. A soliton field algebra is defined as a crossed product with the group of soliton sectors. In this algebra, the nonlocal commutation relations are determined and weak locality, spin statistics and CPT theorems are proven. These theorems depart from their usual appearance due to the broken symmetry connecting the inequivalent vacua. An interpretation of these results in terms of modular theory is given. For the neutral subalgebra of the soliton algebra, the theorems hold in a familiar form, and twisted duality is derived.  相似文献   

17.
The energy conditions in general relativity are introduced to establish powerful theorems without having to restrict their applicability to specific choices of the stress-energy tensor. They are famously invoked, e.g., to prove the singularity theorems of Penrose and Hawking, but have also been applied elsewhere, including various tests of certain cosmological theories. These conditions have become somewhat controversial, however, because they appear to be violated by commonly accepted scenarios, such as inflation shortly after the Big Bang and late-time acceleration of the cosmic expansion. But accommodating these processes by abandoning all of the energy conditions will promote other disquieting possibilities, including the breakdown of causality with traversable wormholes and closed timeloops. This paper advocates for the opposite viewpoint, demonstrating that the ‘numen’ scalar field, derived from the zero active mass condition in general relativity, satisfies all of the energy conditions in the early Universe. This unique feature among scalar fields adds to its success in accounting for the observed properties of the cosmic microwave background better than its inflationary counterpart. Specifically, numen's complete consistency with all of the energy conditions, and inflation's violation of at least one of them, provides additional justification for theoretically favoring the former over the latter.  相似文献   

18.
Automorphic distributions for SL(2) arise as boundary values of modular forms and, in a more subtle manner, from Maass forms. In the case of modular forms of weight one or of Maass forms, the automorphic distributions have continuous first antiderivatives. We recall earlier results of one of us on the Holder continuity of these continuous functions and relate them to results of other authors; this involves a generalization of classical theorems on Fourier series by S. Bernstein and Hardy and Littlewood. We then show that the antiderivatives are non-differentiable at all irrational points, as well as all, or in certain cases, some rational points. We include graphs of several of these functions, which clearly display a high degree of oscillation. Our investigations are motivated in part by properties of Riemann's nondifferentiable function', also known as Weierstrass' function'.  相似文献   

19.
Automorphic distributions for SL(2) arise as boundary values of modular forms and, in a more subtle manner, from Maass forms. In the case of modular forms of weight one or of Maass forms, the automorphic distributions have continuous first antiderivatives. We recall earlier results of one of us on the Holder continuity of these continuous functions and relate them to results of other authors; this involves a generalization of classical theorems on Fourier series by S. Bernstein and Hardy and Littlewood. We then show that the antiderivatives are non-differentiable at all irrational points, as well as all, or in certain cases, some rational points. We include graphs of several of these functions, which clearly display a high degree of oscillation. Our investigations are motivated in part by properties of ‘Riemann’s nondifferentiable function’, also known as ‘Weierstrass’ function’.  相似文献   

20.
R.B. Jones 《Physica A》1979,95(1):104-116
We derive Faxén theorems for the force, the torque and the symmetric force dipole moment acting on a spherically symmetric polymer suspended in an arbitrary time dependent compressible flow. The translational and rotational motions of the polymer are allowed to be non-steady as well. These results extend the theorems already derived for the case of a polymer immersed in a creeping flow.  相似文献   

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