共查询到20条相似文献,搜索用时 10 毫秒
1.
《Physics letters. [Part B]》1988,213(2):160-164
We systematically study the gauge fixing of the Möbius and the super-Möbius transformations for the N-point closed-string amplitudes on the disk. Using the Faddeev-Popov method, we obtain the explicit formulas for the Koba-Nielsen factors for these amplitudes. 相似文献
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3.
Bertfried Fauser 《Czechoslovak Journal of Physics》2000,50(11):1221-1228
In a recent work we have shown that quantum Clifford algebras — i.e. Clifford algebras of an arbitrary bilinear form — are
closely related to the deformed structures asq-spin groups, Hecke algebras,q-Young operators and deformed tensor products. The question to relate Manin’s approach to quantum Clifford algebras is addressed
here. Explicit computations using the CLIFFORD Maple package are exhibited. The meaning of non-commutative geometry is reexamined
and interpreted in Clifford algebraic terms.
Presented at the 9th Colloquium “Quantum Groups and Integrable Systems”, Prague, 22–24 June 2000. 相似文献
4.
《Physics letters. A》1999,259(2):108-114
Closed-form expressions are obtained for the generating function of close-packed dimers on a 2M×2N simple quartic lattice embedded on a Möbius strip and a Klein bottle. Finite-size corrections are also analyzed and compared with those under cylindrical and free boundary conditions. Particularly, it is found that, for large lattices of the same size and with a square symmetry, the number of dimer configurations on a Möbius strip is 70.2% of that on a cylinder. We also establish two identities relating dimer generating functions for Möbius strips and cylinders. 相似文献
5.
P. K. Concha O. Fierro E. K. Rodríguez 《The European Physical Journal C - Particles and Fields》2017,77(1):48
We present a generalization of the standard Inönü–Wigner contraction by rescaling not only the generators of a Lie superalgebra but also the arbitrary constants appearing in the components of the invariant tensor. The procedure presented here allows one to obtain explicitly the Chern–Simons supergravity action of a contracted superalgebra. In particular we show that the Poincaré limit can be performed to a \(D=2+1\) \(\left( p,q\right) \) AdS Chern–Simons supergravity in presence of the exotic form. We also construct a new three-dimensional \(\left( 2,0\right) \) Maxwell Chern–Simons supergravity theory as a particular limit of \(\left( 2,0\right) \) AdS–Lorentz supergravity theory. The generalization for \(\mathcal {N}=p+q\) gravitinos is also considered. 相似文献
6.
On the Schrödinger equation and the eigenvalue problem 总被引:1,自引:0,他引:1
If
k
is thek
th eigenvalue for the Dirichlet boundary problem on a bounded domain in
n
, H. Weyl's asymptotic formula asserts that
, hence
. We prove that for any domain and for all
. A simple proof for the upper bound of the number of eigenvalues less than or equal to - for the operator –V(x) defined on
n
(n3) in terms of
is also provided.Research partially supported by a Sloan Fellowship and NSF Grant No. 81-07911-A1 相似文献
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9.
《Physics letters. A》1998,247(3):207-210
Features of the quantum field theory in the background of the Gödel space-time are investigated. By using the Euclidean approach, a quantum field propagating in this background is found to possess a temperature proportional to the magnitude of the cosmic vorticity. However, in the semiclassical approximation, the Gödel solution does not present an intrinsic entropy. 相似文献
10.
In this paper, exact traveling wave solutions of the conformable differential equations have been examined. By means of the wave transformation and properties of the conformable derivative (CD), conformable nonlinear Schrödinger equation (CNLSE) has been converted into an integer order differential equation. To extract optical solutions, the wave profile has been divided into amplitude and phase components. A new extension of the Bäcklund method has been offered and applied to the CNLSE which has important applications in quantum mechanics. Some novel exact traveling wave solutions to the CNLSE with group velocity dispersion and second order spatiotemporal dispersion coefficients are successfully obtained by means of this method. 相似文献
11.
Reijo Piirainen 《Foundations of Physics》1996,26(2):223-242
The Möbius transformation (MT) was analyzed as a coordinate transformation in the Minkowski form. The transformation function contains three separate light cones. The Weyl spheres were interpreted as basic constituents of local light cones. These cones are related to the denominators of the MT and its inverse, and their apexes define an axis with the top of the global light cone as the centerpoint. That axis represents the local part of the world-line of a moving frame of reference. On the world-line, the scale factor of the MT is proportional to the ratio of the radii of the initial Weyl sphere and the equivalent transformed one. The projection centers, defining the transformation of the world-line, were determined graphically. There are two types of such MT's. Inner transformations have their projetion centers on the axes of the frame at rest, outer transformations on the axes of the observed moving frame. The signature of x
0
2
–r2 is conserved during inner transformations. All possible directions of the world-line of an inertial frame form a timelike mass cone around the time axis of the frame at rest. The mass cone and the related spacelike phase cone may be seen as projections of a lightlike central motion on the surface of a Weyl sphere. Conformal transformations leave both the mass cone and the phase cone invariant: the MT locally, and the Lorentz transformation globally. The moving frame of any lightlike particle rotates by /2 radians, thus exchanging the time axis with one of the space axes. The measurable mass of such a particle is considered to be zero because only the central plane of the particle is space-oriented. The real mass is invariant. To test this hypothesis, the two -quanta produced by the electron pair annihilation should be led to a recollision, for recreating the initial electron-position pair. 相似文献
12.
The two-dimensional quantum superintegrable systems with quadratic integrals of motion on a manifold are classified by using the quadratic associative algebra of the integrals of motion. There are six general fundamental classes of quantum superintegrable systems corresponding to the classical ones. Analytic formulas for the involved integrals are calculated in all the cases. All the known quantum superintegrable systems with quadratic integrals are classified as special cases of these six general classes. The coefficients of the quadratic associative algebra of integrals are calculated and they are compared to the coefficients of the corresponding coefficients of the Poisson quadratic algebra of the classical systems. The quantum coefficients are similar to the classical ones multiplied by a quantum coefficient -?2 plus a quantum deformation of order ?4 and ?6. The systems inside the classes are transformed using Stäckel transforms in the quantum case as in the classical case. The general form of the Stäckel transform between superintegrable systems is discussed. 相似文献
13.
D. J. Cirilo-Lombardo 《Physics of Particles and Nuclei Letters》2009,6(5):359-360
The coherent states for a quantum particle on a Möbius strip are constructed and the relation with the natural phase space for fermionic fields is shown. The explicit comparison of the obtained states with previous works where the cylinder quantization was used and the spin 1/2 was introduced by hand is given. 相似文献
14.
Mark Davidson 《Foundations of Physics》2017,47(3):327-354
The rigid recoil of a crystal is the accepted mechanism for the Mössbauer effect. It’s at odds with the special theory of relativity which does not allow perfectly rigid bodies. The standard model of particle physics which includes QED should not allow any signals to be transmitted faster than the speed of light. If perturbation theory can be used, then the X-ray emitted in a Mössbauer decay must come from a single nuclear decay vertex at which the 4-momentum is exactly conserved in a Feynman diagram. Then the 4-momentum of the final state Mössbauer nucleus must be slightly off the mass shell. This off-shell behavior would be followed by subsequent diffusion of momentum throughout the crystal to bring the nucleus back onto the mass shell and the crystal to a final relaxed state in which it moves rigidly with the appropriate recoil velocity. This mechanism explains the Mössbauer effect at the microscopic level and reconciles it with relativity. Because off-mass-shell quantum mechanics is required, the on-mass-shell theories developed originally for the Mössbauer effect are inadequate. Another possibility is that that the recoil response involves a non-perturbative effect in the standard model which could allow for a non-local instantaneous momentum transfer between the crystal and the decay (or absorption), as proposed for example by Preparata and others in super-radiance theory. The recoil time of the crystal is probably not instantaneous, and if it could be measured, one could distinguish between various theories. An experiment is proposed in this paper to measure this time. The idea is to measure the total energy radiated due to bremsstrahlung from a charged Mössbauer crystal which has experienced a recoil. Using Larmor’s formula, along with corrections to it, allows one to design an experiment. The favored idea is to use many small nano-spheres of Mössbauer-active metals, whose outer surfaces are charged. The energy radiated then varies as the charge squared divided by the recoil time. This can then be measured with the extreme sensitivity available in Mössbauer experiments. If it turns out that experiments prove the need for off-mass-shell theory, then this would have profound implications for all of condensed matter physics. It would mean that an off-mass-shell theory like those considered by Stueckelberg, Horwitz, Piron, Greenberger, and many others are required to describe nature. The inclusion of these would be a major shift in the foundations. It would mean that there are new dynamic variables—the rest masses of particles. The ability to measure the diffusion relaxation time should prove useful also in chemical analysis, and provide a new class of analytical methods for material science. This problem is also interesting because the Mössbauer effect is a phenomenon where the solid-state environment dramatically and indisputably influences the probability of a nuclear process. 相似文献
15.
In many biological systems like whole cells, membranes or proteins and some of the polymeric systems, dynamics reveals itself
in M?ssbauer spectra as a non Lorentzian behaviour above some particular temperature which is characteristic of the system.
Moreover mean square displacement and line width show temperature dependence above the characteristic temperature. Brownian
motion of harmonically bound oscillator has been able to explain the non-Lorentzian behaviour. In the present paper, a quantum
picture of the above model is discussed and lineshape is expressed as the closed form for the extreme overdamping case. In
addition to the non-Lorentzian behaviour, the present model also predicts a temperature dependence of mean square displacement
and linewidth.
Received 16 July 1997 and Received in final form 2 September 1998 相似文献
16.
N. Elstner 《Zeitschrift für Physik B Condensed Matter》1992,87(2):197-202
The quantum nonlinear -model in (d+1)-dimensional space-time is investigated by a renormalization group approach. The beta-functions for the couplingg and the temperaturet are given. The renormalisation group equations of theN-point functions are derived for finite coupling and finite temperature. It is known that the model shows a phase transition at zero temperature at some critical couplingg
c
. The behaviour near this critical point is investigated. The crossover exponent , describing the crossover between different regimes near the critical point is calculated, verifying a conjecture by Chakravarty, Halperin and Nelson, who have argued that ind dimensions should have the same value as the critical exponent of the correlation length in a (d+1)-dimensional classical system. A subtraction scheme appropriate to calculate the renormalisation factors and from these the beta-functions at finite temperature and finite coupling constant will be introduced. Using this method the beta-functions will be calculated to order two loops. The exponents obtained this way are in good agreement with the values found on other ways. 相似文献
17.
We study the finite-size scaling properties of the Ising model on the M?bius strip and the Klein bottle. The results are compared with those of the Ising model under different boundary conditions, that is, the free, cylindrical, and toroidal boundary conditions. The difference in the magnetization distribution function p(m) for various boundary conditions is discussed in terms of the number of the percolating clusters and the cluster size. We also find interesting aspect-ratio dependence of the value of the Binder parameter at T = T(c) for various boundary conditions. We discuss the relation to the finite-size correction calculations for the dimer statistics. 相似文献
18.
Andrzej Witkowski 《Molecular physics》2013,111(20):2423-2432
The Galillei transformation invariant form of molecular quantum mechanics is obtained, which is not restricted by the Born–Oppenheimer approximation. The molecular Hamiltonian takes then the form of a linear combination of operators of the Schrödinger group, which define the new space–time molecular symmetry properties (e.g. helicity). The puzzling homochirality of the hydrogen bonded biomolecular systems appears then as a simple result of the molecular space-time symmetry. 相似文献
19.
Freund I 《Optics letters》2011,36(23):4506-4508
The twist numbers of circular optical M?bius strips and twisted ribbons are shown to obey the index theorem under rotation of the plane of observation, and under change in the radius of the path. 相似文献
20.
V. I. Man'ko G. Marmo E. C. G. Sudarshan F. Zaccaria 《Journal of Russian Laser Research》1999,20(5):421-437
The relation between the density matrix obeying the von Neumann equation and the wave function obeying the Schrödinger equation is discussed in connection with the superposition principle of quantum states. The definition of the ray-addition law is given, and its relation to the addition law of vectors in the Hilbert space of states and the role of a constant phase factor of the wave function is elucidated. The superposition law of density matrices, Wigner functions, and tomographic probabilities describing quantum states in the probability representation of quantum mechanics is studied. Examples of spin-1/2 and Schrödinger-cat states of the harmonic oscillator are discussed. The connection of the addition law with the entanglement problem is considered. 相似文献