arXiv subjects

Sang-Heon Yi

Publications and source records attributed to Sang-Heon Yi.

49 records · Page 3Linked to original sources

arXiv2011

Holographic Renormalization and Stress Tensors in New Massive Gravity

We obtain holographically renormalized boundary stress tensors with the emphasis on a special point in the parameter space of three dimensional new massive gravity, using the so-called Fefferman-Graham coordinates with relevant counter terms. Through the linearized equations of motion with a standard prescription, we also obtain correlators among these stress tensors. We argue that the self-consistency of holographic renormalization determines counter terms up to unphysical ambiguities. Using these renormalized stress tensors in Fefferman-Graham coordinates, we obtain the central charges of dual CFT, and mass and angular momentum of some $AdS$ black hole solutions. These results are consistent with the previous ones obtained by other methods. In this study on the Fefferman-Graham expansion of new massive gravity, some aspects of higher curvature gravity are revealed.

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arXiv2011

Quasi Normal Modes for New Type Black Holes in New Massive Gravity

We obtain the quasi-normal mode frequencies of scalar perturbation on new type black holes in three dimensional new massive gravity. In some special cases, the exact quasi-normal mode frequencies are obtained by solving scalar field equations exactly. On some parameter regions, the highly damped quasi-normal mode frequencies are obtained in an analytic form by the so-called Stokes line method. This study on quasi-normal modes shed some light on the mysterious nature of these black holes. We also comment about AdS/CFT correspondence and the entropy/area spectrum for new type black holes.

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arXiv2010

Mass and Angular momentum of Black Holes in New Massive Gravity

We obtain mass and angular momentum of black holes as conserved charges in three dimensional new massive gravity, after presenting the explicit expression for the potential of the conserved charges. This confirms the expression of those charges obtained in several ways, in particular through AdS/CFT correspondence, and shows us that the first law of black hole thermodynamics is valid in these black holes. We also comment about conserved charges in new type black holes with the emphasis on the AdS/CFT correspondence as guiding principle.

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arXiv2010

AdS Black Hole Solutions in the Extended New Massive Gravity

We have obtained (warped) AdS black hole solutions in the three dimensional extended new massive gravity. We investigate some properties of black holes and obtain central charges of the two dimensional dual CFT. To obtain the central charges, we use the relation between entropy and temperature according to the AdS/CFT dictionary. For AdS black holes, one can also use the central charge function formalism which leads to the same results.

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arXiv2009

Eight Fermion Terms in the Effective Action of the ABJM Model

We study eight fermion terms in the effective action of the ABJM model. We show the non-renormalization of $v^2$ terms. After classifying all the possible eight fermion structures, we show that $\mathcal{N}=6$ supersymmetry determines all these terms completely up to an overall constant. This confirms the one loop non-renormalization of $v^4$ terms.

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arXiv2008

Membrane Dynamics in Three dimensional N=6 Supersymmetric Chern-Simons Theory

We study the membrane scattering in the three-dimensional N=6 supersymmetric Chern-Simons theory recently constructed by Aharony, Bergman, Jafferis and Maldacena and conjectured to be dual to M-theory on $AdS_4 \times S^7/Z_k$. We compute the one-loop effective action up to the $v^4$ terms in the derivative expansion and find exact agreement with the results from the supergravity computations. In particular, our results imply that the $v^2$ term is not renormalized and tree-level exact.

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arXiv2007

Two-dimensional Black Holes in a Higher Derivative Gravity and Matrix Model

We construct perturbatively a class of charged black hole solutions in type 0A string theory with higher derivative terms. They have extremal limit, where the solution interpolates smoothly between near horizon AdS_2 geometry and the asymptotic linear dilaton geometry. We compute the free energy and the entropy of those solution using various methods. In particular, we show that there is no correction in the leading term of the free energy in the large charge limit. This supports the duality of the type 0A strings on the extremal black hole and the 0A matrix model in which the tree level free energy is exact without any alpha' corrections.

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arXiv2006

Non-compact Topological Branes on Conifold

We consider non-compact branes in topological string theories on a class of Calabi-Yau spaces including the resolved conifold and its mirror. We compute the amplitudes of the insertion of non-compact Lagrangian branes in the A-model on the resolved conifold in the context of the topological vertex as well as the melting crystal picture. They all agree with each other and also agree with the results from Chern-Simons theory, supporting the large N duality. We find that they obey the Schrödinger equation confirming the wavefunction behavior of the amplitudes. We also compute the amplitudes of the non-compact B-branes in the DV matrix model which arises as a B-model open string field theory on the mirror manifold of the deformed conifold. We take the large N duality to consider the B-model on the mirror of the resolved conifold and confirm the wave function behavior of this amplitude. We find appropriate descriptions of non-compact branes in each model, which give complete agreements among those amplitudes and clarify the salient features including the role of symmetries toward these agreements.

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arXiv2005

Topological B-model and ${\hat c}=1$ String Theory

We study the topological B-model on a deformed $\Z_2$ orbifolded conifold by investigating variation of complex structures via quantum Kodaira-Spencer theories. The fermionic/brane formulation together with systematic utilization of symmetries of the geometry gives rise to a free fermion realization of the amplitudes. We derive Ward identities which solve the perturbed free energy exactly. We also obtain the corresponding Kontsevich-like matrix model. All these confirm the recent conjecture on the connection of the theory with ${\hat c}=1$ type 0A string theory compactified at the radius $R=\sqrt{α'/2}$.

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arXiv2003

Thermodynamic behavior of IIA string theory on a pp-wave

We obtain the thermal one loop free energy and the Hagedorn temperature of IIA superstring theory on the pp-wave geometry which comes from the circle compactification of the maximally supersymmetric eleven dimensional one. We use both operator and path integral methods and find the complete agreement between them in the free energy expression. In particular, the free energy in the $μ\to \infty$ limit is shown to be identical with that of IIB string theory on maximally supersymmetric pp-wave, which indicates the universal thermal behavior of strings in the large class of pp-wave backgrounds. We show that the zero point energy and the modular properties of the free energy are naturally incorporated into the path integral formalism.

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arXiv2003

3D N=2 massive super Yang-Mills and membranes/D2-branes in a curved background

We present a three dimensional novel massive N=2 super Yang-Mills action as a low energy effective worldvolume description of the D2-branes on a pp-wave. The action contains the Myers term, mass terms for three Higgs, and terms mixing the electric fields with other two Higgs. We derive the action in three different ways, from the M-theory matrix model, from the supermembrane action, and from the Dirac-Born-Infeld action. We verify the consistent mutual agreement and comment how each approach is complementary to another. In particular, we give the eleven dimensional geometric interpretation of the vacua in the worldvolume theory as the membranes tilted to the eleventh direction with the giant gravitons around.

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arXiv2002

1/4 BPS Dyonic Calorons

We explore the 1/4 BPS configurations of the supersymmetric gauge theories on $R^{1+3} \times S^1$. The BPS bound for energy and the BPS equations are obtained and the characteristics of the BPS solutions are studied. These BPS configurations describe electrically charged calorons, which are constituted of dyons and carry linear momentum along the compact direction. We carry out various approaches to the single caloron case in the theory of SU(2) gauge group.

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arXiv2002

Tales of D0 on D6 Branes: Matrix Mechanics of Identical Particles

We investigate a class of matrix model which describes the dynamics of identical particles in even dimentional space. We show that the degrees of freedom after some constraints are implimented is proportional to particle number and consist of those for positions and internal degrees. The particle dynamics is given by the metric on the smooth moduli space. The moduli space metric for two particles is found. The size of tightly packed $N$ particles grows like $\sqrt{N}$. Our matrix model is related to the matrix model for fractional quantum Hall effect, the ADHM formalism of U(1) instantons on noncommutative space, and supersymmetric D0 branes on D6 branes with nonzero B-field in type IIA theory.

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