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1.
The symmetrical character of empty space–time is proposed as a putative reason for mirror symmetry violations in the bioorganic world and in the world of elementary particles, and a new geometrical model for the empty space–time is put forward. In contrast to flat four-dimensional Minkowski space, this model is described by a cylindrical four-dimensional space metrics. The geodesic lines of this space are helical. The helical structure of the model proposed shows that distortion of mirror symmetry may be a consequence of geometrical structure of the empty space rather than a characteristic of any specific interaction. 相似文献
2.
We have considered the possibility of formation of a massless particles with spin 1 in the region of negative energies, within the framework of the Weyl-type equation for neutrinos. It is proved that the represented approach allows to get a stable structural formation in the ground state, which can be interpreted as a fundamental massless particle. The structure and properties of this vector boson are studied in detail. The problem of entangling two vector bosons with projections of spins +1 and −1 and, accordingly, the formation of a zero-spin boson is studied within the framework of a complex stochastic matrix equations of the Langevin type. The paper discusses the structure of the Bose particle of a scalar field and the space–time properties of an empty space (quantum vacuum). 相似文献
3.
In the standard formalism of quantum gravity, black holes appear to form statistical distributions of quantum states. Now, however, we can present a theory that yields pure quantum states. It shows how particles entering a black hole can generate firewalls, which however can be removed, replacing them by the ‘footprints’ they produce in the out-going particles. This procedure can preserve the quantum information stored inside and around the black hole. We then focus on a subtle but unavoidable modification of the topology of the Schwarzschild metric: antipodal identification of points on the horizon. If it is true that vacuum fluctuations include virtual black holes, then the structure of space-time is radically different from what is usually thought. 相似文献
4.
We study the geodesic motion of pseudo-classical spinning particles in the NUT–Reissner–Nordstrom space–time. We investigate the generalized Killing equations for spinning space and derive the constants of the motion in terms of the solutions of these equations. We give an analysis of the motion on a cone and on a plane. 相似文献
6.
A new type of magnetic core-shell Ni–Ce nanocomposite particles (15–50 nm) is presented. SEM observations suggest the particles are strongly ferromagnetic, interacting with ordered chain-like features. Typical HR-TEM images demonstrate that many planar defects (nanotwins and stacking faults) exist in the surface shell and large Ni core zone (10–40 nm) of the particles; the inner shell layers (4–6 nm) consist of NiCe alloy and the outermost shell is NiO. Nano-diffraction patterns show an indication of well-defined spots characteristic of nanocomposite materials, of which certain crystal facet orientation relationships between orthorhombic [111] of NiCe and cubic [311] of Ni 2Ce, face-center crystal [222] of NiO, cubic [111] of nickel have been identified. This confirms the nature of this core-shell nanocomposite particle. 相似文献
7.
We discuss the question of whether or not a general Weyl structure is a suitable mathematical model of space–time. This is an issue that has been in debate since Weyl formulated his unified field theory for the first time. We do not present the discussion from the point of view of a particular unification theory, but instead from a more general standpoint, in which the viability of such a structure as a model of space–time is investigated. Our starting point is the well known axiomatic approach to space–time given by Elhers, Pirani and Schild (EPS). In this framework, we carry out an exhaustive analysis of what is required for a consistent definition for proper time and show that such a definition leads to the prediction of the so-called “second clock effect”. We take the view that if, based on experience, we were to reject space–time models predicting this effect, this could be incorporated as the last axiom in the EPS approach. Finally, we provide a proof that, in this case, we are led to a Weyl integrable space–time as the most general structure that would be suitable to model space–time. 相似文献
8.
We present and discuss the Klein–Gordonand Dirac wave equations in the de Sitter universe. Toobtain the Dirac wave equation we use the factorizationof the second-order invariant Casimir operatorassociated to the Fantappie–de Sitter group. Boththe Klein–Gordon and Dirac wave equations arediscussed in terms of the spherical harmonics with spinweight. A particular case of Dirac wave equation issolved in terms of a new class of polynomials. 相似文献
9.
Abstract The paper contains a symmetry classification of the one–dimensional second order equation of a hydrodynamical type L( Lu)+ λLu= F ( u), where L ≡ ? t+ u? x. Some classes of exact solutions of this equation are given. 相似文献
10.
We calculate the free energy and the entropy of a scalar field in terms of the brick-wall method in the background of the Schwarzschild–de Sitter space–time. We obtain the entropy of a black hole and the cosmic entropy at nonasymptotic flat space. When the cut-off satisfies the proper condition, the entropy of a black hole is proportional to the area of a black hole horizon, and the cosmic entropy is proportional to the cosmic horizon area. 相似文献
11.
The phase structure of a (2+1)-dimensional Gross–Neveu model with four different channels of fermion–antifermion interaction, and, correspondingly, four different coupling constants, is studied. It is shown that the model describes five different phases of the interaction of planar fermions in which either spatial parity or chiral symmetry can be broken. The existence of a phase that is characterized by simultaneous spontaneous breaking of both these symmetries that was not observed earlier in such models is demonstrated. 相似文献
12.
Whitham–Broer–Kaup(WBK) equations in the shallow water small-amplitude regime is hereby under investigation. Nonlocal symmetry and Bcklund transformation are presented via the truncated Painlevé expansion.This residual symmetry is localised to Lie point symmetry by the properly enlarged system. The finite symmetry transformation of the prolonged system is computed. Based on the CTE method, WBK equations are linearized and new analytic interaction solutions between solitary waves and cnoidal waves are given with the aid of solutions for the linear equation. 相似文献
13.
The purpose of this paper is to correct errors presented recently in the paper [Lv et al. J Stat Phys 149:619–628 ( 2012)], where the authors analyzed Fractional Fokker–Planck equation (FFPE) with space–time dependent drift $F(x,t)=F(x)f(t)$ and diffusion $D(x,t)=D(x)\tilde{d}(t)$ coefficients in the factorized form. We show an important drawback in the derivation of the stochastic representation of FFPE presented in the aforementioned paper, which makes the whole proof wrong. Moreover, we present a correct proof of their result in even more general case, when both drift and diffusion can have any, not necessarily factorized, form. 相似文献
14.
ABSTRACTStructure and physical properties of 25CaO– xPbO–(75– x)P 2O 5 (0≤ x≤35) glasses are investigated in this paper. Substitution of PbO for P 2O 5 in the binary 25CaO–75P 2O 5 glass was found to increase the density and to decrease the molar volume. Fourier transform infrared (FTIR) and Raman spectroscopies show the evolution of the phosphate skeleton when the PbO content increases: Q 3 to Q 2 species (0< x≤25) and Q 2 phosphate network ( x = 25) to short phosphate groups ( x > 25) such as (P 4O 136?) ( x = 35). The glass transition temperature first decreases with x, then increases for x values larger than 10%. The evolution of the glass transition temperatures is interpreted from the structural data: the minimum point observed in Tg is attributed to the transition of the ultraphosphate network from the network containing the modifying cations at isolated sites to a network with modifier sub-structure sharing terminal oxygens. At higher PbO content, the large increase in Tg is due to the reticulation of the phosphate network by PbO 4 groups. 相似文献
15.
The structure, stability and energetics of ionic arsenic–water complexes [As 3+– nH 2O ( n?=?1–5) and As 5+– nH 2O ( n?=?3–5)] have been studied in detail using the MP2 method. Both the trivalent and pentavalent ionic states of arsenic were considered. The change in binding energy of the complexes with increasing number of water molecules was investigated. For both complexes involving trivalent and pentavalent arsenic, highly intense modes are observed in the high-frequency region. The structure and symmetry of the complexes with increasing number of water molecules is discussed. The charge transfer in these complexes is illustrated with the help of the natural electron configuration. Both donation and back-donation processes involving the orbitals of oxygen and arsenic are analysed to explain the charge transfer. 相似文献
16.
We discuss the effect of Aharonov-Bohm magnetic flux on the time reversal symmetric properties of mesoscopic metallic ring systems.It is usually believed that AB flux causes time reversal symmetry breaking.We analyse the case of mesoscopic persistent currents and find out that AB flux does not break time reversal symmetry.our arguments are supported by the general theory of mesoscopic persistent currents. 相似文献
17.
Abstract Using the subgroup structure of the generalized Poincaré group P (1, 4), ansatzes which reduce the Euler–Lagrange–Born–Infeld, multidimensional Monge–Ampere and eikonal equations to differential equations with fewer independent variables have been constructed. Among these ansatzes there are ones which reduce the considered equations to linear ordinary differential equations. The corresponding symmetry reduction has been done. Using the solutions of the reduced equations, some classes of exact solutions of the investigated equation have been presented. 相似文献
18.
We investigate the evolution of non-adiabatic collapse of a shear-free spherically symmetric stellar configuration with anisotropic stresses accompanied with radial heat flux. The collapse begins from a curvature singularity with infinite mass and size on an inhomogeneous space–time background. The collapse is found to proceed without formation of an even horizon to singularity when the collapsing configuration radiates all its mass energy. The impact of inhomogeneity on various parameters of the collapsing stellar configuration is examined in some specific space–time backgrounds. 相似文献
19.
We suggest a simple but general method of establishing symmetry properties of stable solutions of nonlinear elliptic equations. The method relies on characterization of symmetry breaking with a help of zero modes and on a generalization of the Perron–Frobenius theory. 相似文献
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