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1.
We present the bundle (Aff(3)Λ)(ℝ3), with a geometric Dirac equation on it, as a three-dimensional geometric interpretation of the SM fermions. Each (ℂΛ)(ℝ3) describes an electroweak doublet. The Dirac equation has a doubler-free staggered spatial discretization on the lattice space (Aff(3)ℂ)(ℤ3). This space allows a simple physical interpretation as a phase space of a lattice of cells. We find the SM SU(3) c ×SU(2) L ×U(1) Y action on (Aff(3)Λ)(ℝ3) to be a maximal anomaly-free gauge action preserving E(3) symmetry and symplectic structure, which can be constructed using two simple types of gauge-like lattice fields: Wilson gauge fields and correction terms for lattice deformations. The lattice fermion fields we propose to quantize as low energy states of a canonical quantum theory with ℤ2-degenerated vacuum state. We construct anticommuting fermion operators for the resulting ℤ2-valued (spin) field theory. A metric theory of gravity compatible with this model is presented too.  相似文献   

2.
We consider a lattice scalar field model with higher derivative terms in the action whose phase diagram contains a tricritical point which is also a triple point between the paramagnetic, ferromagnetic and antiferromagnetic phases. The continuum limit is defined by approching the tricritical point from the paramagnetic side. Contrary to the lattice tricritical g6ϕ6 model we can do a perturbative computation in dimension four. The non-perturbative aspect of the theory relies on the dispersion relation which has the particular feature of having several minima similar to the propagator of lattice fermions. It is shown that this new model is perturbatively renormalizable and provides a non trivial mass spectrum. The positive norm Hilbert space and the unitarity of the time evolution operator in Minkowski space is established by means of the reflection positivity property.  相似文献   

3.
The integrability of string model of WZNW model type with constant SU(2), SO(3), SP(2) torsion is investigated. The closed boson string model in the background gravity and antisymmetric B-field is considered as integrable system in terms of initial chiral currents. The model is considered under assumption that internal torsion related with metric of Riemann-Cartan space and external torsion related with antisymmetric B-field are (anti)coincide. New equation of motion and exact solution this equation was obtained for string model with constant SU(2), SO(3), SP(2) torsion. New equations of motion and new Poisson brackets (PB) for infinite dimensional hydrodynamic chains was obtained for string model with constant SU(n), SO(n), SP(n) torsion for n → ∞.  相似文献   

4.
The SO q (N)-invariant Schrödinger equation for the free particle is formulated in polar coordinates as a partial differential equation in noncommutative geometry. For each value of the total angular momentum, a Hilbert space of radial functions is constructed as the space of normalizable functions respective to the q-integral. The spectrum of the Hamiltonian is found to be discrete.  相似文献   

5.
We describe a large new class of four‐dimensional supersymmetric string vacua defined as compactifications of the E8 × E8 and the SO(32) heterotic string on smooth Calabi‐Yau threefolds with unitary gauge bundles and heterotic five‐branes. The conventional gauge symmetry breaking via Wilson lines is replaced by the embedding of non‐flat line bundles into the ten‐dimensional gauge group, thus opening up the way for phenomenologically interesting string compactifications on simply connected manifolds. After a detailed analysis of the four‐dimensional effective theory we exemplify the general framework by means of a couple of explicit examples involving the spectral cover construction of stable holomorphic bundles. As for the SO(32) heterotic string, the resulting vacua can be viewed, in the S‐dual Type I picture, as a generalisation of magnetized D9/D5‐brane models. In the case of the E8 × E8 string, we find a natural way to construct realistic MSSM‐like models, either directly or via a flipped SU(5) GUT scenario.  相似文献   

6.
The B-model topological string theory on a Calabi-Yau threefold X has a symmetry group Γ, generated by monodromies of the periods of X. This acts on the topological string wave function in a natural way, governed by the quantum mechanics of the phase space H 3(X). We show that, depending on the choice of polarization, the genus g topological string amplitude is either a holomorphic quasi-modular form or an almost holomorphic modular form of weight 0 under Γ. Moreover, at each genus, certain combinations of genus g amplitudes are both modular and holomorphic. We illustrate this for the local Calabi-Yau manifolds giving rise to Seiberg-Witten gauge theories in four dimensions and local IP 2 and IP 1 × IP 1. As a byproduct, we also obtain a simple way of relating the topological string amplitudes near different points in the moduli space, which we use to give predictions for Gromov-Witten invariants of the orbifold .  相似文献   

7.
We review known real forms of the quantum orthogonal groups SO q (N). New *-conjugations are then introduced and we contruct all real forms of quantum orthogonal groups. We thus give an RTT formulation of the *-conjugations on SO q (N) that is complementary to the U q (g) *-structure classification of Twietmeyer. In particular, we easily find and describe the real forms SO q (N-1,1) for any value of N. Quantum subspaces of the q-Minkowski space are analyzed.  相似文献   

8.
We examine basis functions on momentum space for the three-dimensional Euclidean Snyder algebra. We argue that the momentum space is isomorphic to the SO(3) group manifold, and that the basis functions span either one of two Hilbert spaces. This implies the existence of two distinct lattice structures of space. Continuous rotations and translations are unitarily implementable on these lattices.  相似文献   

9.
The group SO(6) ⊗ SO(5) is shown to be the gauge group as well as supersymmetry group of a four dimensional superstring model. Here, we discuss how supersymmetry is realised in 4-dimensions and further, we successfully reproduce the gauge symmetry results. Using the SO(6) ⊗ SO(5) group, all the known aspects of the string theory are obtained. The model reduces to the Standard Model which has the capability of containing the ingredients of a successful theory of the present day physics. However, there are no Higgs in the model.  相似文献   

10.
We construct the Euclidean Green functions for the soliton (magnetic monopole) field in the U(1)4 Lattice Gauge Theory with Wilson action. We show that in the strong coupling regime there is monopole condensation while in the QED phase the physical Hilbert space splits into orthogonal soliton sectors labeled by integer magnetic charge. Received: 2 July 1997 / Accepted: 20 July 1998  相似文献   

11.
We develop a group-theoretical approach to the formulation of generalized abelian gauge theories, such as those appearing in string theory and M-theory. We explore several applications of this approach. First, we show that there is an uncertainty relation which obstructs simultaneous measurement of electric and magnetic flux when torsion fluxes are included. Next, we show how to define the Hilbert space of a self-dual field. The Hilbert space is Z2-graded and we show that, in general, self-dual theories (including the RR fields of string theory) have fermionic sectors. We indicate how rational conformal field theories associated to the two-dimensional Gaussian model generalize to (4k + 2)-dimensional conformal field theories. When our ideas are applied to the RR fields of string theory we learn that it is impossible to measure the K-theory class of a RR field. Only the reduction modulo torsion can be measured.  相似文献   

12.
In this contribution nuclear representations of the Dirac ring, developed over many years, are shown to be a particular case of a theorem in algebraic geometry which at the same time associates them with a Hodge decomposition of a Kaehler manifold. This yields a shape that in some cases is independent of any appeal to a symmetry group. However, because the nuclear representations are in the infinitesimal ring of SO(4) and the internal space of each representation is in a Kaehler (even Calabi-Yau) manifold K; the group SO(10) = SO(4) × K can give additional information. This paper develops the very fruitful symbiosis between algebra and irreducible representations of SO(10) and covers some aspects of string theory.  相似文献   

13.
The spin–lattice relaxation times and spin–spin relaxation times for 1H and M in M5H3(SO4)4·H2O (M=Na, K, Rb, and Cs) single crystals grown using the slow-evaporation method were measured as functions of temperature. Two kinds of protons were identified in the M5H3(SO4)4·H2O structure: acid protons and water protons. Our experimental results show that the acid and water protons in Cs5H3(SO4)4·H2O are involved in phase transitions of this crystal, whereas neither type of proton is involved in the phase transitions of the other three crystal type (M5H3(SO4)4·H2O; M=Na, K, and Rb). Moreover, the relaxation times for the M (=Na, K, and Rb) nuclei in these crystals were found to decrease with increasing temperature and can be described with (k=2). The T1 results for M (=Na, K, and Rb) in M5H3(SO4)4·H2O crystals can be explained in terms of a relaxation mechanism in which the lattice vibrations are coupled to the nuclear electric quadrupole moments.  相似文献   

14.
The spatial string tension across a crossover from the low-temperature phase to the high-temperature phase is computed in QCD with two flavors of nonperturbatively improved Wilson fermions at small lattice spacing a ∼ 0.12 fm. We find that in the low-temperature phase spatial string tension agrees well with zero-temperature string tension. Furthermore, it does not show increasing for temperatures up to T = 1.36T pc, the highest temperature considered. Our results agree with some theoretical predictions. The text was submitted by the authors in English.  相似文献   

15.
A fundamental problem in contemporary string/M theory is to count the number of inequivalent vacua satisfying constraints in a string theory model. This article contains the first rigorous results on the number and distribution of supersymmetric vacua of type IIb string theories compactified on a Calabi-Yau 3-fold X with flux. In particular, complete proofs of the counting formulas in Ashok-Douglas [AD] and Denef-Douglas [DD1] are given, together with van der Corput style remainder estimates.Supersymmetric vacua are critical points of certain holomorphic sections (flux superpotentials) of a line bundle over the moduli space of complex structures on X × T 2 with respect to the Weil-Petersson connection. Flux superpotentials form a lattice of full rank in a 2 b 3(X)-dimensional real subspace . We show that the density of critical points in for this lattice of sections is well approximated by Gaussian measures of the kind studied in [DSZ1,DSZ2,AD,DD1].Research partially supported by DOE grant DE-FG02-96ER40959 (first author) and NSF grants DMS-0100474 (second author) and DMS-0302518 (third author).  相似文献   

16.
A comparative analysis has been carried out on the Raman spectra of FeSO4·nH2O (n = 1, 4, 7) including the 2D‐analogs. The effects of changing the degrees of hydration have been found from the lattice, SO42− internal, and H2O internal modes. Increasing degrees of hydration shift the intense ν1(SO4) peak to lower wavenumbers and reduce the amount of splitting on the ν3(SO4) peaks. Some of the water librational bands cause the broadening of the ν4(SO4) peaks in FeSO4·7H2O and the ν2(SO4) peaks in FeSO4·7D2O. The ν2(H2O) band in FeSO4·H2O is red‐shifted in excess of 100 cm−1 relative to the unperturbed H2O band. Between 240 and 190 K and between 140 and 90 K in the spectra of FeSO4.4H2O, two potential phase transitions have been identified from the changes in the lattice and water‐stretching regions. The resolution of the ν1(H2O) and ν3(H2O) bands in FeSO4·4H2O and FeSO4·H2O also improved sharply at low temperatures. The capability of distinguishing various forms of FeSO4 hydrates unambiguously makes the Raman technique a potential analytical tool for the identification of sulfate minerals on planetary surfaces. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

17.
A geometric construction of a certain singular unitary representation ofSO e(p,q), withp+q even is given. The representation is realized geometrically as the kernel of aSO e(p,q)-invariant operator on a space of sections over a homogeneous space forSO e(p,q). TheK-structure of these representations is elucidated and we demonstrate their unitarity by explicitly writing down anso(p,q) positive definite hermitian form. Finally, we demonstrate that the annihilator inU[g] of this representation is the Joseph ideal, which is the maximal primitive ideal associated with the minimal coadjoint orbit.  相似文献   

18.
The experimental data carried out by M?ssbauer and magnetic resonances investigations of the structural phase transitions in K2ZnCl4 crystals are discussed by a simple electrostatic model, calculating, the lattice contributions to the local electric potential V(r), electric field intensity E(r) and electric field gradient tensor, (r) and taking into account both the fractional electric point charges and rigid lattice approximations. The validity of the model is proved by a good fit of the computing results and experimental data of quadrupole splitting parameters at K sites obtained by 39K-NMR methods in high temperature incommensurate phase ( Pnam symmetry). The experimental results obtained by M?ssbauer and EPR methods in commensurate phase (Pna21 symmetry) of iron and copper doped K2ZnCl4 crystals are explained by relaxing the rigid lattice approximation. The insertion of probe ions appear to be done on not-exactly-Zn2+ site. Received 3 February 1999 and Received in final form 4 May 1999  相似文献   

19.
We study a class of subdivision invariant lattice models based on the gauge groupZ p , with particular emphasis on the four dimensional example. This model is based upon the assignment of field variables to both the 1- and 2-dimensional simplices of the simplicial complex. The property of subdivision invariance is achieved when the coupling parameter is quantized and the field configurations are restricted to satisfy a type of mod-p flatness condition. By explicit computation of the partition function for the manifoldRP 3×S 1, we establish that the theory has a quantum Hilbert space which differs from the classical one.Supported by Stichting voor Fundamenteel Onderzoek der Materie (FOM)  相似文献   

20.
We study a 3D generalization of the toric code model introduced recently by Chamon. This is an exactly solvable spin model with six-qubit nearest-neighbor interactions on an FCC lattice whose ground space exhibits topological quantum order. The elementary excitations of this model which we call monopoles can be geometrically described as the corners of rectangular-shaped membranes. We prove that the creation of an isolated monopole separated from other monopoles by a distance R requires an operator acting on Ω(R2) qubits. Composite particles that consist of two monopoles (dipoles) and four monopoles (quadrupoles) can be described as end-points of strings. The peculiar feature of the model is that dipole-type strings are rigid, that is, such strings must be aligned with face-diagonals of the lattice. For periodic boundary conditions the ground space can encode 4g qubits where g is the greatest common divisor of the lattice dimensions. We describe a complete set of logical operators acting on the encoded qubits in terms of closed strings and closed membranes.  相似文献   

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