Publications (20)7.37 Total impact
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Article: Hawking Radiation via Higher-spin Gauge Anomalies
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ABSTRACT: We give a higher-spin generalization of the anomaly method for the Hawking radiation from black holes. In the paper arXiv:0710.0453 higher-spin generalizations of the gauge (and gravitational) anomalies in d=2 were obtained. By applying these anomalies to black hole physics, we derive the higher moments of the Hawking fluxes. We also give a higher-spin generalization of the trace anomaly method by Christensen and Fulling.11/2007; -
Article: Fluxes of Higher-spin Currents and Hawking Radiations from Charged Black Holes
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ABSTRACT: This is an extended version of the previous paper (hep-th/0701272). Quantum fields near horizons can be described in terms of an infinite set of two-dimensional conformal fields. We first generalize the method of Christensen and Fulling to charged black holes to derive fluxes of energy and charge. These fluxes can be obtained by employing a conformal field theory technique. We then apply this technique to obtain the fluxes of higher-spin currents and show that the thermal distribution of Hawking radiation from a charged black hole can be completely reproduced by investigating transformation properties of the higher-spin currents under conformal and gauge transformations.06/2007; -
Article: Higher-spin Currents and Thermal Flux from Hawking Radiation
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ABSTRACT: Quantum fields near black hole horizons can be described in terms of an infinite set of d=2 conformal fields. In this paper, by investigating transformation properties of general higher-spin currents under a conformal transformation, we reproduce the thermal distribution of Hawking radiation in both cases of bosons and fermions. As a byproduct, we obtain a generalization of the Schwarzian derivative for higher-spin currents.03/2007; -
Article: Quantum Anomalies at Horizon and Hawking Radiations in Myers-Perry Black Holes
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ABSTRACT: A new method has been developed recently to derive Hawking radiations from black holes based on considerations of gravitational and gauge anomalies at the horizon gr-qc/0502074 hep-th/0602146. In this paper, we apply the method to Myers-Perry black holes with multiple angular momenta in various dimensions by using the dimensional reduction technique adopted in the case of four-dimensional rotating black holes hep-th/0606018. Comment: 15 pages, typos corrected, minor corrections12/2006; -
Article: Anomalies, Hawking Radiations and Regularity in Rotating Black Holes
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ABSTRACT: This is an extended version of our previous letter hep-th/0602146. In this paper we consider rotating black holes and show that the flux of Hawking radiation can be determined by anomaly cancellation conditions and regularity requirement at the horizon. By using a dimensional reduction technique, each partial wave of quantum fields in a d=4 rotating black hole background can be interpreted as a (1+1)-dimensional charged field with a charge proportional to the azimuthal angular momentum m. From this and the analysis gr-qc/0502074, hep-th/0602146 on Hawking radiation from charged black holes, we show that the total flux of Hawking radiation from rotating black holes can be universally determined in terms of the values of anomalies at the horizon by demanding gauge invariance and general coordinate covariance at the quantum level. We also clarify our choice of boundary conditions and show that our results are consistent with the effective action approach where regularity at the future horizon and vanishing of ingoing modes at r=\infty are imposed (i.e. Unruh vacuum).07/2006; -
Article: Hawking radiation from charged black holes via gauge and gravitational anomalies.
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ABSTRACT: Extending the method of Robinson and Wolczek, we show that in order to avoid a breakdown of general covariance and gauge invariance at the quantum level the total flux of charge and energy in each outgoing partial wave of a charged quantum field in a Reissner-Nordström black hole background must be equal to that of a (1 + 1)-dimensional blackbody at the Hawking temperature with the appropriate chemical potential.Physical Review Letters 05/2006; 96(15):151302. · 7.37 Impact Factor -
Article: Fermionic Backgrounds and Condensation of Supergravity Fields in IIB Matrix Model
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ABSTRACT: In a previous paper hep-th/0410182 we constructed wave functions and vertex operators for massless supergravity fields in type IIB matrix model by expanding supersymmetric Wilson line operators. In this paper we consider fermionic backgrounds and condensation of supergravity fields in IIB matrix model by using these wave functions. We start from the type IIB matrix model in a flat background whose matrix size is $(N+1) \times (N+1)$, or equivalently the effective action for $(N+1)$ D-instantons. We then calculate an effective action for $N$ D-instantons by integrating out one D-instanton (which we call a mean-field D-instanton) with an appropriate wave function and show that various terms can be induced corresponding to the choice of the wave functions. In particular, a Chern-Simons-like term is induced when the mean-field D-instanton has a wave function of the antisymmetric tensor field. A fuzzy sphere becomes a classical solution to the equation of motion for the effective action. We also give an interpretation of the above wave functions from the string theory side as overlaps of the D-instanton boundary state with closed string massless states in the Green-Schwarz formalism. Comment: 32 pages, Latex; discussion clarified. version to appear in Phys. Rev. D03/2005; -
Article: Wilson Loops and Vertex Operators in Matrix Model
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ABSTRACT: We systematically construct wave functions and vertex operators in the type IIB (IKKT) matrix model by expanding a supersymmetric Wilson loop operator. They form a massless multiplet of the N=2 type IIB supergravity and automatically satisfy conservation laws. Comment: 26 pages, no figures, typos corrected, version accepted for publication in Phys.Rev.D10/2004; -
Article: Note on Gauge Theory on Fuzzy Supersphere
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ABSTRACT: We construct a supermatrix model whose classical background gives two-dimensional noncommutative supersphere. Quantum fluctuations around it give the supersymmetric gauge theories on the fuzzy supersphere constructed by Klimcik. This model has a parameter $\beta$ which can tune masses of the particles in the model and interpolate various supersymmetric gauge theories on sphere. Comment: 13 pages, LaTeX12/2003; -
Article: Gauge Theory on Noncommutative Supersphere from Supermatrix Model
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ABSTRACT: We construct a supermatrix model which has a classical solution representing the noncommutative (fuzzy) two-supersphere. Expanding supermatrices around the classical background, we obtain a gauge theory on a noncommutative superspace on sphere. This theory has $osp(1|2)$ supersymmetry and $u(2L+1|2L)$ gauge symmetry. We also discuss a commutative limit of the model keeping radius of the supersphere fixed. Comment: 16 pages, Latex, typos corrected, references added11/2003; -
Article: Generalized Gauge Theories and Weinberg-Salam Model with Dirac-K\"ahler Fermions
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ABSTRACT: We extend previously proposed generalized gauge theory formulation of Chern-Simons type and topological Yang-Mills type actions into Yang-Mills type actions. We formulate gauge fields and Dirac-K\"ahler matter fermions by all degrees of differential forms. The simplest version of the model which includes only zero and one form gauge fields accommodated with the graded Lie algebra of $SU(2|1)$ supergroup leads Weinberg-Salam model. Thus the Weinberg-Salam model formulated by noncommutative geometry is a particular example of the present formulation. Comment: 33 pages, LaTeX10/2000; -
Article: A Conserved Energy Integral for Perturbation Equations in the Kerr-de Sitter Geometry
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ABSTRACT: The analytic proof of mode stability of the Kerr black hole was provided by Whiting. In his proof, the construction of a conserved quantity for unstable mode was crucial. We extend the method of the analysis for the Kerr-de Sitter geometry. The perturbation equations of massless fields in the Kerr-de Sitter geometry can be transformed into Heun's equations which have four regular singularities. In this paper we investigate differential and integral transformations of solutions of the equations. Using those we construct a conserved quantity for unstable modes in the Kerr-de Sitter geometry, and discuss its property. Comment: 13 pages, LaTeX05/2000; -
Article: Absorption rate of the Kerr-de Sitter black hole and the Kerr-Newman-de Sitter black hole
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ABSTRACT: By using an analytic solution of the Teukolsky equation in the Kerr-de Sitter and Kerr-Newman-de Sitter geometries, an analytic expression of the absorption rate formulae for these black holes is calculated. Comment: 11 pages, LaTeX. Several typos are corrected11/1999; -
Article: Analytic Solutions of Teukolsky Equation in Kerr-de Sitter and Kerr-Newman-de Sitter Geometries
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ABSTRACT: The analytic solution of Teukolsky equation in Kerr-de Sitter and Kerr-Newman-de Sitter geometries is presented and the properties of the solution are examined. In particular, we show that our solution satisfies the Teukolsky-Starobinsky identities explicitly and fix the relative normalization between solutions with the spin weight $s$ and $-s$. Comment: 24 pages, LaTeX05/1999; -
Article: Perturbations of Kerr-de Sitter Black Hole and Heun's Equations
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ABSTRACT: It is well known that the perturbation equations of massless fields for the Kerr-de Sitter geometry can be written in the form of separable equations. The equations have five definite singularities so that the analysis has been expected to be difficult. We show that these equations can be transformed to Heun's equations, for which we are able to use known technique for the analysis of the solutions. We reproduce results known previously for the Kerr geometry and de Sitter geometry in the confluent limits of the Heun's functions. Our analysis applies can be extended to Kerr-Newman-de Sitter geometry for massless fields with spin 0 and 1/2. Comment: 17 pages, LaTeX05/1998; -
Article: Quantization of even-dimensional actions of Chern-Simons form with infinite reducibility
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ABSTRACT: We investigate the quantization of even-dimensional topological actions of Chern-Simons from which have been proposed earlier. We quantize the actions by Lagrangian and Hamiltonian formulations à la Batalin, Fradkin and Vilkovisky. The models turn out to be infinitely reducible and thus we need an infinite number of ghosts and antighosts. The minimal actions of the Lagrangian formulation which satisfy the master equation of Batalin and Vilkovisky have the same Chern-Simons form as the starting classical actions. In the Hamiltonian formulation we have used the formulation of cohomological perturbation and explicitly show that the gauge-fixed actions of both formulations coincide even though the classical action breaks Dirac's regularity condition. We find the interesting relation that the BRST charge of the Hamiltonian formulation is the odd-dimensional fermionic counterpart of the topological action of Chem-Simons form. Although the quantization of two-dimensional models which include both bosonic and fermionic gauge fields are investigated in detail, it is straightforward to extend the quantization into arbitrary even dimensions. This completes the quantization of previously proposed topological gravities in two and four dimensions.Nuclear Physics B. 04/1998; -
Article: Quantization of Infinitely Reducible Generalized Chern-Simons Actions in Two Dimensions
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ABSTRACT: We investigate the quantization of two-dimensional version of the generalized Chern-Simons actions which were proposed previously. The models turn out to be infinitely reducible and thus we need infinite number of ghosts, antighosts and the corresponding antifields. The quantized minimal actions which satisfy the master equation of Batalin and Vilkovisky have the same Chern-Simons form. The infinite fields and antifields are successfully controlled by the unified treatment of generalized fields with quaternion algebra. This is a universal feature of generalized Chern-Simons theory and thus the quantization procedure can be naturally extended to arbitrary even dimensions. Comment: 17 pages, LaTeX02/1997; -
Article: Noncommutative superspace, supermatrix and lowest Landau level
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ABSTRACT: By using graded (super-)Lie algebras, we can construct noncommutative superspace on curved homogeneous manifolds. In this paper, we take a flat limit to obtain flat noncommutative superspace. We particularly consider d=2 and d=4 superspaces based on the graded Lie algebras osp(1|2), su(2|1) and psu(2|2). Jacobi identities of supersymmetry algebras and associativities of star products are automatically satisfied. Covariant derivatives which commute with supersymmetry generators are obtained and chiral constraints can be imposed. We also discuss that these noncommutative superspaces can be understood as constrained systems analogous to the lowest Landau level system.Nuclear Physics B. -
Article: Generalized conformal symmetry and recovery of SO(8) in multiple M2 and D2 branes
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ABSTRACT: We investigate conformal symmetries of the Aharony–Bergman–Jafferis–Maldacena (ABJM) theory for multiple M2 branes and the Lorentzian Bagger–Lambert–Gustavsson (L-BLG) theory which can be obtained by taking a scaling limit k(≫N)→∞ of the ABJM theory. The conformal symmetry is maintained in the L-BLG by considering general space–time varying solutions to the constraint equations. The dual geometry is reduced to d=10AdS4×CP3 in the scaling limit and has the same conformal symmetry. The curvature radius R satisfies ( and ls are the d-dimensional Planck lengths and the string scale), and the theory is in a region where an α′ expansion is not valid. We also study how the SO(8) covariance is recovered in the AdS4×CP3 geometry by taking the scaling limit.Nuclear Physics B. -
Article: Higher-spin gauge and trace anomalies in two-dimensional backgrounds
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ABSTRACT: Two-dimensional quantum fields in electric and gravitational backgrounds can be described by conformal field theories, and hence all the physical (covariant) quantities can be written in terms of the corresponding holomorphic quantities. In this paper, we first derive relations between covariant and holomorphic forms of higher-spin currents in these backgrounds, and then, by using these relations, obtain higher-spin generalizations of the trace and gauge (or gravitational) anomalies up to spin 4. These results are applied to derive higher-moments of Hawking fluxes in black holes in a separate paper [S. Iso, T. Morita, H. Umetsu, Hawking radiation via higher-spin gauge anomalies, arXiv: 0710.0456 [hep-th]].Nuclear Physics B.
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Institutions
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1998
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Hokkaido University
- Department of Physics
Sapporo-shi, Hokkaido, Japan
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