367 research outputs found

    Trace formula for dielectric cavities III: TE modes

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    The construction of the semiclassical trace formula for the resonances with the transverse electric (TE) polarization for two-dimensional dielectric cavities is discussed. Special attention is given to the derivation of the two first terms of Weyl's series for the average number of such resonances. The obtained formulas agree well with numerical calculations for dielectric cavities of different shapes.Comment: 12 pages, 6 figure

    Composite non-Abelian Flux Tubes in N=2 SQCD

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    Composite non-Abelian vortices in N=2 supersymmetric U(2) SQCD are investigated. The internal moduli space of an elementary non-Abelian vortex is CP^1. In this paper we find a composite state of two coincident non-Abelian vortices explicitly solving the first order BPS equations. Topology of the internal moduli space T is determined in terms of a discrete quotient CP^2/Z_2. The spectrum of physical strings and confined monopoles is discussed. This gives indirect information about the sigma model with target space T.Comment: 37 pages, 7 figures, v3 details added, v4 erratum adde

    Semi-classical calculations of the two-point correlation form factor for diffractive systems

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    The computation of the two-point correlation form factor K(t) is performed for a rectangular billiard with a small size impurity inside for both periodic or Dirichlet boundary conditions. It is demonstrated that all terms of perturbation expansion of this form factor in powers of t can be computed directly by semiclassical trace formula. The main part of the calculation is the summation of non-diagonal terms in the cross product of classical orbits. When the diffraction coefficient is a constant our results coincide with expansion of exact expressions ontained by a different method.Comment: 42 pages, 10 figures, Late

    Analogies between self-duality and stealth matter source

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    We consider the problem of a self-interacting scalar field nonminimally coupled to the three-dimensional BTZ metric such that its energy-momentum tensor evaluated on the BTZ metric vanishes. We prove that this system is equivalent to a self-dual system composed by a set of two first-order equations. The self-dual point is achieved by fixing one of the coupling constant of the potential in terms of the nonminimal coupling parameter. At the self-dual point and up to some boundary terms, the matter action evaluated on the BTZ metric is bounded below and above. These two bounds are saturated simultaneously yielding to a vanishing action for configurations satisfying the set of self-dual first-order equations.Comment: 6 pages. To be published in Jour. Phys.

    Det-Det Correlations for Quantum Maps: Dual Pair and Saddle-Point Analyses

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    An attempt is made to clarify the ballistic non-linear sigma model formalism recently proposed for quantum chaotic systems, by the spectral determinant Z(s)=Det(1-sU) of a quantized map U element of U(N). More precisely, we study the correlator omega_U(s)= (averaging t over the unit circle). Identifying the group U(N) as one member of a dual pair acting in the spinor representation of Spin(4N), omega_U(s) is expanded in terms of irreducible characters of U(N). In close analogy with the ballistic non-linear sigma model, a coherent-state integral representation of omega_U(s) is developed. We show that the leading-order saddle-point approximation reproduces omega_U(s) exactly, up to a constant factor; this miracle can be explained by interpreting omega_U(s) as a character of U(2N), for which the saddle-point expansion yields the Weyl character formula. Unfortunately, this decomposition behaves non-smoothly in the semiclassical limit, and to make further progress some averaging over U needs to be introduced. Several averaging schemes are investigated. In general, a direct application of the saddle-point approximation to these schemes is demonstrated to give incorrect results; this is not the case for a `semiclassical averaging scheme', for which all loop corrections vanish identically. As a side product of the dual pair decomposition, we compute a crossover between the Poisson and CUE ensembles for omega_U(s)

    Domain Lines as Fractional Strings

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    We consider N=2 supersymmetric quantum electrodynamics (SQED) with 2 flavors, the Fayet--Iliopoulos parameter, and a mass term β\beta which breaks the extended supersymmetry down to N=1. The bulk theory has two vacua; at β=0\beta=0 the BPS-saturated domain wall interpolating between them has a moduli space parameterized by a U(1) phase σ\sigma which can be promoted to a scalar field in the effective low-energy theory on the wall world-volume. At small nonvanishing β\beta this field gets a sine-Gordon potential. As a result, only two discrete degenerate BPS domain walls survive. We find an explicit solitonic solution for domain lines -- string-like objects living on the surface of the domain wall which separate wall I from wall II. The domain line is seen as a BPS kink in the world-volume effective theory. We expect that the wall with the domain line on it saturates both the {1,0}\{1,0\} and the {1/2,1/2}\{{1/2},{1/2}\}b central charges of the bulk theory. The domain line carries the magnetic flux which is exactly 1/2 of the flux carried by the flux tube living in the bulk on each side of the wall. Thus, the domain lines on the wall confine charges living on the wall, resembling Polyakov's three-dimensional confinement.Comment: 28 pages, 13 figure, v2 typos fixed and reference adde

    Percolation model for nodal domains of chaotic wave functions

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    Nodal domains are regions where a function has definite sign. In recent paper [nlin.CD/0109029] it is conjectured that the distribution of nodal domains for quantum eigenfunctions of chaotic systems is universal. We propose a percolation-like model for description of these nodal domains which permits to calculate all interesting quantities analytically, agrees well with numerical simulations, and due to the relation to percolation theory opens the way of deeper understanding of the structure of chaotic wave functions.Comment: 4 pages, 6 figures, Late

    Semi-Meissner state and neither type-I nor type-II superconductivity in multicomponent systems

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    Traditionally, superconductors are categorized as type-I or type-II. Type-I superconductors support only Meissner and normal states, while type-II superconductors form magnetic vortices in sufficiently strong applied magnetic fields. Recently there has been much interest in superconducting systems with several species of condensates, in fields ranging from Condensed Matter to High Energy Physics. Here we show that the type-I/type-II classification is insufficient for such multicomponent superconductors. We obtain solutions representing thermodynamically stable vortices with properties falling outside the usual type-I/type-II dichotomy, in that they have the following features: (i) Pippard electrodynamics, (ii) interaction potential with long-range attractive and short-range repulsive parts, (iii) for an n-quantum vortex, a non-monotonic ratio E(n)/n where E(n) is the energy per unit length, (iv) energetic preference for non-axisymmetric vortex states, "vortex molecules". Consequently, these superconductors exhibit an emerging first order transition into a "semi-Meissner" state, an inhomogeneous state comprising a mixture of domains of two-component Meissner state and vortex clusters.Comment: in print in Phys. Rev. B Rapid Communications. v2: presentation is made more accessible for a general reader. Latest updates and links to related papers are available at the home page of one of the authors: http://people.ccmr.cornell.edu/~egor

    On the spacing distribution of the Riemann zeros: corrections to the asymptotic result

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    It has been conjectured that the statistical properties of zeros of the Riemann zeta function near z = 1/2 + \ui E tend, as EE \to \infty, to the distribution of eigenvalues of large random matrices from the Unitary Ensemble. At finite EE numerical results show that the nearest-neighbour spacing distribution presents deviations with respect to the conjectured asymptotic form. We give here arguments indicating that to leading order these deviations are the same as those of unitary random matrices of finite dimension Neff=log(E/2π)/12ΛN_{\rm eff}=\log(E/2\pi)/\sqrt{12 \Lambda}, where Λ=1.57314...\Lambda=1.57314 ... is a well defined constant.Comment: 9 pages, 3 figure

    Trace formula for dieletric cavities : I. General properties

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    The construction of the trace formula for open dielectric cavities is examined in detail. Using the Krein formula it is shown that the sum over cavity resonances can be written as a sum over classical periodic orbits for the motion inside the cavity. The contribution of each periodic orbit is the product of the two factors. The first is the same as in the standard trace formula and the second is connected with the product of reflection coefficients for all points of reflection with the cavity boundary. Two asymptotic terms of the smooth resonance counting function related with the area and the perimeter of the cavity are derived. The coefficient of the perimeter term differs from the one for closed cavities due to unusual high-energy asymptotics of the S\mathbf{S}-matrix for the scattering on the cavity. Corrections to the leading semi-classical formula are briefly discussed. Obtained formulas agree well with numerical calculations for circular dielectric cavities.Comment: 13 pages, 10 figure
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