arXiv subjects
Publications and source records attributed to H. S. Sharatchandra.
In this note we point out links between the Shimura - Taniyama conjecture and certain ideas in physics. Since all the seminal references are by strange coincidence Japanese we wish to call this the Japanese approach. The note elaborates on some inspired comments made by Barry Mazur in his popular article "Number theory as gadfly."
It is shown that the SO(3) gauge field configurations can be completely characterised by certain gauge invariant vector fields. The singularities of these vector fields describe the topological aspects of the gauge field configurations. The topological (or monopole) charge is expressed in terms of an Abelian vector potential.
The entropy of an orthogonal matrix is defined. It provides a new interpretation of Hadamard matrices as those that saturate the bound for entropy.It appears to be a useful Morse function on the group manifold. It has sharp maxima and other saddle points. The matrices corresponding to the maxima for 3 and 5 dimensions are presented. They are integer matrices (upto a rescaling).
An explicit canonical transformation is constructed to relate the physical subspace of Yang-Mills theory to the phase space of the ADM variables of general relativity. This maps 3+1 dimensional Yang-Mills theory to local evolution of metrics on 3 manifolds.
Non-Abelian Gauss law is interpreted in terms of area bits described in a local frame which fit together into closed surfaces and the Non-Abelian Stokes law in terms of length bits described in a local frame which fit together into closed loops. A new equation relating the area variables and the phase space variables (or equivalently, angular momentum variables of the lattice Yang-Mills theory and phase space variables of the continuum theory) is obtained. Canonical quantization applied to these variables implies area quantization. A complete orthonormal basis of states satisfying the Gauss constraint is obtained.It has the interpretation of quantized area bits with undefined orientations and edges but fitting together into closed surfaces.
An explicit canonical transformation is constructed to relate the physical subspace of Yang-Mills theory to the phase space of the ADM variables of general relativity. This maps 3+1 dimensional Yang-Mills theory to local evolution of metrics on 3 manifolds.
The problem of Wu-Yang ambiguities in 3 dimensions is related to the problem of existence of torsion free driebeins for an arbitrary potential. The ambiguity is only at the level of boundary conditions. We also find that in 3 dimensions any smooth Yang-Mills field tensor can be uniquely written as the non-Abelian magnetic field of a smooth Yang-Mills potential.
Dual form of 3+1 dimensional Yang-Mills theory is obtained as another SO(3) gauge theory. Duality transformation is realized as a canonical transformation. The The non-abelian Gauss law implies the corresponding Gauss law for the dual theory. The dual theory is non-local. There is a non-local version of Yang-Mills theory which is self dual.
We make a numerical study of the finite temperature properties of the SO(3) lattice gauge theory. As its symmetry properties are quite different from those of the SU(2) LGT, a different set of observables have to be considered in this model. We study several observables, such as, the plaquette square, the Z(2) monopole density, the fundamental and adjoint Wilson line, and the tiled Wilson line correlation function. Our simulations show that the Z(2) monopoles condense at strong coupling just as in the bulk system. This transition is seen at approximately the same location as in the bulk system. A surprising observation is the multiple valuedness of the adjoint Wilson line at high temperatures. At high temperatures, we observe long lived metastable states in which the adjoint Wilson line takes positive and negative values. The numerical values of other observables in these two states appear to be almost the same. We study these states using different methods and also make comparisons with the high temperature behaviour of the SU(2) LGT. Finally, we discuss various interpretations of our results and point out their relevance for the phase diagram of the SO(3) LGT at finite temperature.
New collective coordinates, related to the field at the `center' of the monopoles, are proposed. A systematic computation of the infrared properties of 2+1- and 3+1- dimensional Yang-Mills theory is now possible and is related to solutions of classical equations with constraints at isolated points. For 2+1-dimensional Yang-Mills theory, monopoles of a specific size proportional to $g^{-2}$ dominate and a semiclassical technique is applicable. For 3+1-dimensional Yang-Mills theory, the formalism incorporates a monopole condensate naturally, and is therefore a correct starting point for computations of confinement properties. The method also provides a precise way of going beyond the dilute gas approximation for instantons in 3+1-dimensions. Another algorithm, which uses only the quadratic form of the action and corrections via renormalized perturbation theory, is proposed as a viable scheme of computation for all length scales.
2+1-dimensional Yang-Mills theory is reinterpreted in terms of metrics on 3-manifolds. The dual gluons are related to diffeomorphisms of the 3-manifold. Monopoles are identified with points where the Ricci tensor has triply degenerate eigenvalues. The dual gluons have the desired interaction with these monopoles. This would give a mass for the dual gluons resulting in confinement.
General solution of the non-abelian Gauss law in terms of covariant curls and gradients is presented. Also two non-abelian analogs of the Hodge decomposition in three dimensions are addressed. i) Decomposition of an isotriplet vector field $V_{i}^{a}(x)$ as sum of covariant curl and gradient with respect to an arbitrary background Yang-Mills potential is obtained. ii) A decomposition of the form $V_{i}^{a}=B_{i}^{a}(C)+D_{i}(C) ϕ^{a} $ which involves non-abelian magnetic field of a new Yang-Mills potential C is also presented. These results are relevant for duality transformation for non-abelian gauge fields.
We construct wave packets for the hydrogen atom labelled by the classical action-angle variables with the following properties. i) The time evolution is exactly given by classical evolution of the angle variables. (The angle variable corresponding to the position on the orbit is now non-compact and we do not get exactly the same state after one period. However the gross features do not change. In particular the wave packet remains peaked around the labels.) ii) Resolution of identity using this overcomplete set involves exactly the classical phase space measure. iii) Semi-classical limit is related to Bohr-Sommerfield quantization. iv) They are almost minimum uncertainty wave packets in position and momentum.
We develop various complementary concepts and techniques for handling quantum fluctuations of Goldstone bosons.We emphasise that one of the consequences of the masslessness of Goldstone bosons is that the longitudinal fluctuations also have a diverging susceptibility characterised by an anomalous dimension $(d-2)$ in space-time dimensions $2<d<4$.In $d=4$ these fluctuations diverge logarithmically in the infrared region.We show the generality of this phenomenon by providing three arguments based on i). Renormalization group flows, ii). Ward identities, and iii). Schwinger-Dyson equations.We obtain an explicit form for the generating functional of one-particle irreducible vertices of the O(N) (non)--linear $σ$--models in the leading 1/N approximation.We show that this incorporates all infrared behaviour correctly both in linear and non-linear $σ$-- models. Our techniques provide an alternative to chiral perturbation theory.Some consequences are discussed briefly.
Requirements of a conjugate operator are emphasized, especially in its role in uncertainty relations.It is argued that in many contexts it is necessary to extend the Hilbert space in order to define a conjugate operator as in gauge theories. Example of a particle in a box is analysed. This is closely related to the quantum oscillator through cosine states of Susskind and Glogower.It is used to justify London's phase wave functions albeit as part of a larger Hilbert space. A new definition phase uncertainty neccessiated by periodicity is proposed.It is close to the usual r.m.s. definition.Corresponding number- phase uncertainty relation is obtained and its implications are discussed. Hilbert space of an oscillator is identified with the Hilbert space of a planar rotor with a $Z_2$ gauge invariance.This is used to construct states analogous to the cosine and sine states and to illustrate unitary equivalence of Hilbert spaces.
Unique set of coherent states for the anharmonic oscillator is obtained by requiring i. under the quantum mechanical time evolution a coherent state evolves into another, governed by trajectory in the classical phase space (of a related hamiltonian); ii. the resolution of identity involves exactly the classical phase space measure.The rules are invariant under unitary transformations of the quantum theory and canonical transformations of the classical theory. The states are almost, but not quite, minimal uncertainty wave packets. The construction can be generalized to quantum versions of integrable classical theories.
Chiral perturbation theory has to be substantially modified for the problem of nuclear forces. Loop effects dominate over tree level effects. The dominant behaviours in the scalar isoscalar channel and multi-nucleon forces are obtained in the chiral limit and for a small explicit breaking.
We develop a simple computational tool for $SU(3)$ analogous to Bargmann's calculus for $SU(2)$. Crucial new inputs are, (i) explicit representation of the Gelfand-Zetlin basis in terms of polynomials in four variables and positive or negative integral powers of a fifth variable (ii) an auxiliary Gaussian measure with respect to which the Gelfand-Zetlin states are orthogonal but not normalized (iii) simple generating functions for generating all basis states and also all invariants. As an illustration of our techniques, an algebraic formula for the Clebsch-Gordan coefficients is obtained for the first time. This involves only Gaussian integrations. Thus $SU(3)$ is made as accessible for computations as $SU(2)$ is.