82 research outputs found

    Logarithmic intertwining operators and W(2,2p-1)-algebras

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    For every p≥2p \geq 2, we obtained an explicit construction of a family of W(2,2p−1)\mathcal{W}(2,2p-1)-modules, which decompose as direct sum of simple Virasoro algebra modules. Furthermore, we classified all irreducible self-dual W(2,2p−1)\mathcal{W}(2,2p-1)-modules, we described their internal structure, and computed their graded dimensions. In addition, we constructed certain hidden logarithmic intertwining operators among two ordinary and one logarithmic W(2,2p−1)\mathcal{W}(2,2p-1)-modules. This work, in particular, gives a mathematically precise formulation and interpretation of what physicists have been referring to as "logarithmic conformal field theory" of central charge cp,1=1−6(p−1)2p,p≥2c_{p,1}=1-\frac{6(p-1)^2}{p}, p \geq 2. Our explicit construction can be easily applied for computations of correlation functions. Techniques from this paper can be used to study the triplet vertex operator algebra W(2,(2p−1)3)\mathcal{W}(2,(2p-1)^3) and other logarithmic models.Comment: 22 pages; v2: misprints corrected, other minor changes. Final version to appear in Journal of Math. Phy

    A monomial basis for the Virasoro minimal series M(p,p') : the case 1<p'/p<2

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    Quadratic relations of the intertwiners are given explicitly in two cases of chiral conformal field theory, and monomial bases of the representation spaces are constructed by using the Fourier components of the intertwiners. The two cases are the (p,p')-minimal series for the Virasoro algebra where 1<p'/p<2, and the level k integrable highest weight modules for the affine Lie algebra \hat{sl}_2.Comment: Latex, 29 page

    The Impact of Non-Equipartition on Cosmological Parameter Estimation from Sunyaev-Zel'dovich Surveys

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    The collisionless accretion shock at the outer boundary of a galaxy cluster should primarily heat the ions instead of electrons since they carry most of the kinetic energy of the infalling gas. Near the accretion shock, the density of the intracluster medium is very low and the Coulomb collisional timescale is longer than the accretion timescale. Electrons and ions may not achieve equipartition in these regions. Numerical simulations have shown that the Sunyaev-Zel'dovich observables (e.g., the integrated Comptonization parameter Y) for relaxed clusters can be biased by a few percent. The Y-mass relation can be biased if non-equipartition effects are not properly taken into account. Using a set of hydrodynamical simulations, we have calculated three potential systematic biases in the Y-mass relations introduced by non-equipartition effects during the cross-calibration or self-calibration when using the galaxy cluster abundance technique to constraint cosmological parameters. We then use a semi-analytic technique to estimate the non-equipartition effects on the distribution functions of Y (Y functions) determined from the extended Press-Schechter theory. Depending on the calibration method, we find that non-equipartition effects can induce systematic biases on the Y functions, and the values of the cosmological parameters Omega_8, sigma_8, and the dark energy equation of state parameter w can be biased by a few percent. In particular, non-equipartition effects can introduce an apparent evolution in w of a few percent in all of the systematic cases we considered. Techniques are suggested to take into account the non-equipartition effect empirically when using the cluster abundance technique to study precision cosmology. We conclude that systematic uncertainties in the Y-mass relation of even a few percent can introduce a comparable level of biases in cosmological parameter measurements.Comment: 10 pages, 3 figures, accepted for publication in the Astrophysical Journal, abstract abridged slightly. Typos corrected in version

    Vertex operators and the geometry of moduli spaces of framed torsion-free sheaves

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    We define complexes of vector bundles on products of moduli spaces of framed rank r torsion-free sheaves on the complex projective plane. The top non-vanishing Chern classes of the cohomology of these complexes yield actions of the r-colored Heisenberg and Clifford algebras on the equivariant cohomology of the moduli spaces. In this way we obtain a geometric realization of the boson-fermion correspondence and related vertex operators.Comment: 36 pages; v2: Definition of geometric Heisenberg operators modified; v3: Minor typos correcte

    Weight Vectors of the Basic A_1^(1)-Module and the Littlewood-Richardson Rule

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    The basic representation of \A is studied. The weight vectors are represented in terms of Schur functions. A suitable base of any weight space is given. Littlewood-Richardson rule appears in the linear relations among weight vectors.Comment: February 1995, 7pages, Using AMS-Te

    Polynomial Identities, Indices, and Duality for the N=1 Superconformal Model SM(2,4\nu)

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    We prove polynomial identities for the N=1 superconformal model SM(2,4\nu) which generalize and extend the known Fermi/Bose character identities. Our proof uses the q-trinomial coefficients of Andrews and Baxter on the bosonic side and a recently introduced very general method of producing recursion relations for q-series on the fermionic side. We use these polynomials to demonstrate a dual relation under q \rightarrow q^{-1} between SM(2,4\nu) and M(2\nu-1,4\nu). We also introduce a generalization of the Witten index which is expressible in terms of the Rogers false theta functions.Comment: 41 pages, harvmac, no figures; new identities, proofs and comments added; misprints eliminate

    Fusion products, Kostka polynomials, and fermionic characters of su(r+1)_k

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    Using a form factor approach, we define and compute the character of the fusion product of rectangular representations of \hat{su}(r+1). This character decomposes into a sum of characters of irreducible representations, but with q-dependent coefficients. We identify these coefficients as (generalized) Kostka polynomials. Using this result, we obtain a formula for the characters of arbitrary integrable highest-weight representations of \hat{su}(r+1) in terms of the fermionic characters of the rectangular highest weight representations.Comment: 21 pages; minor changes, typos correcte

    Combinatorial Identities and Quantum State Densities of Supersymmetric Sigma Models on N-Folds

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    There is a remarkable connection between the number of quantum states of conformal theories and the sequence of dimensions of Lie algebras. In this paper, we explore this connection by computing the asymptotic expansion of the elliptic genus and the microscopic entropy of black holes associated with (supersymmetric) sigma models. The new features of these results are the appearance of correct prefactors in the state density expansion and in the coefficient of the logarithmic correction to the entropy.Comment: 8 pages, no figures. To appear in the European Physical Journal

    SM(2,4k) fermionic characters and restricted jagged partitions

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    A derivation of the basis of states for the SM(2,4k)SM(2,4k) superconformal minimal models is presented. It relies on a general hypothesis concerning the role of the null field of dimension 2k−1/22k-1/2. The basis is expressed solely in terms of GrG_r modes and it takes the form of simple exclusion conditions (being thus a quasi-particle-type basis). Its elements are in correspondence with (2k−1)(2k-1)-restricted jagged partitions. The generating functions of the latter provide novel fermionic forms for the characters of the irreducible representations in both Ramond and Neveu-Schwarz sectors.Comment: 12 page

    Fermionic Quasi-Particle Representations for Characters of {(G^{(1)})_1 \times (G^{(1)})_1 \o (G^{(1)})_2}

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    We present fermionic quasi-particle sum representations for some of the characters (or branching functions) of ~{(G^{(1)})_1 \times (G^{(1)})_1 \o (G^{(1)})_2} ~for all simply-laced Lie algebras GG. For given GG the characters are written as the partition function of a set of rank~GG types of massless quasi-particles in certain charge sectors, with nontrivial lower bounds on the one-particle momenta. We discuss the non-uniqueness of the representations for the identity character of the critical Ising model, which arises in both the A1A_1 and E8E_8 cases.Comment: 14/9 pages in harvmac, ITP-SB-92-64/RU-92-51. References adde
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