arXiv subjects

Soo-Jong Rey

Publications and source records attributed to Soo-Jong Rey.

At least 109 records · Page 6Linked to original sources

arXiv2000

A Note on D-Branes of Odd Codimensions from Noncommutative Tachyons

On a noncommutative space of rank-1, we construct a codimension-one soliton explicitly and, in the context of noncommutative bosonic open string field theory, identify it with the D24-brane. We compute the tension of the proposed D24-brane, yielding an exact value and show that it is related to the tension of the codimension two D23-brane by the string T-duality. This resolves an apparent puzzle posed by the result of Harvey, Kraus, Larsen and Martinec and proves that the T-duality is a gauge symmetry; in particular, at strong noncommutativity, it is part of the U(oo) gauge symmetry on the worldvolume. We also apply the result to non-BPS D-branes in superstring theories and argue that the codimension-one soliton gives rise to new descent relation among the non-BPS D-branes in Type IIA and Type IIB string theories via T-duality.

hep-th↗

arXiv2000

Open Wilson Lines in Noncommutative Gauge Theory and Tomography of Holographic Dual Supergravity

We study the issue of gauge-invariant observables in d=4, N=4 noncommutative gauge theory and UV-IR relation therein. We show that open Wilson lines form a complete set of gauge invariant operators, which are local in momentum space and, depending on their size, exhibit two distinct behaviors of the UV-IR relation. We next study these properties in a proposed dual description in terms of supergravity and find agreement.

hep-th↗

arXiv1999

More CFTs and RG Flows from Deforming M2/M5-Brane Horizon

Near-horizon geometry of coincident M2-branes at a conical singularity is related to M-theory on AdS4 times an appropriate seven-dimensional manifold X7. For X_7=N^{0,1,0}, squashing deformation is known to lead to spontaneous (super) symmetry breaking from N=(3, 0) to N=(0, 1) in gauged AdS4 supergravity. Via AdS/CFT correspondence, it is interpreted as renormalization group flow of strongly coupled three-dimensional field theory with SU(3)*SU(2) global symmetry. The flow interpolates between N=(0,1) fixed point in the UV to N=(3,0)fixed point in the IR. Evidences for the interpretation are found both from critical points of the supergravity scalar potential and from conformal dimension of relevant chiral primary operators at each fixed point. We also analyze cases with X7=SO(5)/SO(3)_{max}, V_{5,2}(R), M^{1,1,1}, Q^{1,1,1} and find that there is no nontrivial renormalization group flows. We extend the analysis to Englert type vacua of M-theory. By analyzing de Wit-Nicolai potential, we find that deformation of S7 gives rise to renormalization group flow from N=8, SO(8) invariant UV fixed point to N=1, G_2 invariant IR fixed point. For AdS_7 supergravity relevant for near-horizon geometry of coincident M5-branes, we also point out a nontrivial renormalization group flow from N=1 superconformal UV fixed point to non-supersymmetric IR fixed point.

hep-th↗

arXiv1999

Three-Dimensional CFTs and RG Flow from Squashing M2-Brane Horizon

Utilizing AdS/CFT correspondence in M-theory, an example of interacting d=3 conformal field theories and renormalization group flow between them is presented. Near-horizon geometry of N coincident M2-branes located on a conical singularity on eight-dimensional hyperkähler manifold or manifold with Spin(7) holonomy is, in large-N limit, AdS4*X7, where X7 is seven-sphere with squashing. Deformation from round $§_7$ to squashed one is known to lead to spontaneous breaking of N=8 local supersymmetry in gauged AdS4 supergravity to N=1, 0. Via AdS/CFT correspondence, it is interpreted as renormalization group flow from SO(5)*SO(3) symmetric UV fixed point to SO(8) symmetric IR fixed point. Evidences for the interpretation are found both from supergravity scalar potential and existence of interpolating static domain-wall thereof, and from conformal dimensions of relevant chiral primary operator at each fixed point.

hep-th↗

arXiv1999

Holography Principle and Topology Change in String Theory

D-instantons of Type IIB string theory are Ramond-Ramond counterpart of Giddings-Strominger wormholes connecting two asymptotic regions of spacetime. Such wormholes, according to Coleman, might lead to spacetime topology change, third-quantized baby universes and probabilistic determination of fundamental coupling parameters. Utilizing correspondence between AdS5 x M5 Type IIB supergravity and d=4 super Yang-Mills theory, we point out that topology change and sum over topologies not only take place in string theory but also are required for consistency with holography. Nevertheless, the effects of D-instanton wormholes remain completely deterministic, in sharp contrast to Coleman's scenario.

hep-th↗

arXiv1999

Thermodynamics of Large-N Super Yang-Mills Theory and AdS/CFT Correspondence

Thermodynamics of d=4, N=4 supersymmetric SU(N) Yang-Mills theory is studied with particular attention on perturbative expansion at weak `t Hooft coupling regime and interpolation to strong coupling regime thereof. Non-ideal gas effect to free-energy is calculated and found that leading- and next-to-leading-order corrections contribute with relative opposite sign. Pade approximant method is adopted to improve fixed-order, perturbative series and is found to decrease free-energy monotonically as `t Hooft coupling parameter is increased. This may be regarded as an indication of smooth interpolation of thermodynamics between weak and strong `t Hooft coupling regimes, as suggested by Maldacena's AdS/CFT correspondence.

hep-th↗

arXiv1999

Stable Non-BPS Membranes on M(atrix) Orientifold

Examples of stable, non-BPS M-theory membrane configuration are constructed via M(atrix) theory. The stable membranes are localized on O4 or O8 orientifolds, which projects Chan-Paton gauge bundle of M(atrix) zero-brane partons to USp-type. The examples are shown to be consistent with prediction based on K-theory analysis.

hep-th↗

arXiv1999

Holographic View of Causality and Locality via Branes in AdS/CFT Correspondence

We study dynamical aspects of holographic correspondence between d=5 anti-de Sitter supergravity and $d=4$ super Yang-Mills theory. We probe causality and locality of ambient spacetime from super Yang-Mills theory by studying transmission of low-energy brane waves via an open string stretched between two D3-branes in Coulomb branch. By analyzing two relevant physical threshold scales, we find that causality and locality is encoded in the super Yang-Mills theory provided infinite tower of long supermultiplet operators are added. Massive W-boson and dual magnetic monopole behave more properly as extended, bilocal objects. We also study causal time-delay of low-energy excitation on heavy quark or meson and find an excellent agreement between anti-de Sitter supergravity and super Yang-Mills theory descriptions. We observe that strong `t Hooft coupling dynamics and holographic scale-size relation thereof play a crucial role to the agreement of dynamical processes.

hep-th↗

arXiv1998

Green-Schwarz Superstring on AdS3 * S3

Green-Schwarz action of Type IIB string on $AdS_3 \times S^3$ is constructed via coset superspace approach. The construction relies exclusively on symplectically Majorana-Weyl spinor formalism, thus permitting it easier to prove $κ$-symmetry for on-shell Type IIB supergravity backgrounds.

hep-th↗

arXiv1998

Non-Supersymmetric Stable Vacua of M-Theory

We discuss stability of non-supersymmetric compactification of M-theory and string theory of the form AdS * X, and their dual non-supersymmetric interacting conformal field theories. We argue some of the difficulties in controlling 1/N-corrections disappear in the cases that the large-N dual conformal field theory has no invariant marginal operators (and in some cases with no exactly marginal operators only). We provide several examples of such compactifications of M-theory down to AdS4.

hep-th↗

arXiv1998

Holographic Principle and String Cosmology

String cosmology is revisited from cosmological viewpoint of holographic principle put forward by `t Hooft, and by Fischler and Susskind. It is shown that the holography requires existence of a `graceful exit' mechanism, which renders the Universe nonsingular by connecting pre- and post-big bang phases smoothly. It is proven that flat Universe is consistent with the holography only if it starts with an absolutely cold and vacuous state. Particle entropy produced during the `graceful exit' apparently saturates the holography bound. Open Universe can always satisfy the holography no matter what initial state of the Universe is.

hep-th↗

arXiv1998

Dual D-Brane Actions on $AdS^5 \times S^5$

Utilizing coset superspace approach, dual actions of super D1-and D3-branes on $AdS_5 \times S^5$ are constructed by carrying out duality transformation of world-volume U(1) gauge field. Resulting world-volume actions are shown to possess expected SL(2,{\bf Z}) properties. Crucial ingredient for deriving SL(2, {\bf Z}) transformation property of the D-brane actions is covariance of SU(2,2|4) coset superspace algebra under SO(2) rotation between two ten-dimensional Type IIB Majorana-Weyl spinors.

hep-th↗

arXiv1998

M(atrix) Theory on T5/Z2 Orbifold and Five-Branes

We study M(atrix) theory description of M theory compactified on T5/Z2 orbifold. In the large volume limit we show that M theory dynamics is described by N=8 supersymmetric USp(2N) M(atrix) quantum mechanics. Via zero-brane parton scattering, we show that each orbifold fixed point carries anomalous G-flux $\oint [G/2 π]= - 1/2$. To cancel the anomalous G-flux, we introduce twisted sector consisting of sixteen five-branes represented by fundamental representation hypermultiplets. In the small volume limit we show that M theory dynamics is described by by (5+1)-dimensional (8,0) supersymmetric USp(2N) chiral gauge theory. We point out that both perturbative and global gauge anomalies are cancelled by the sixteen fundamental representation hyper- multiplets in the twisted sector. We show that M(atrix) theory is capable of turning on spacetime background with the required sixteen five-branes out of zero-brane partons as bound-states. We determine six-dimensional spacetime spectrum from the M(atrix) theory for both untwisted and twisted sectors and find a complete agreement with the spectrum of (2,0) supergravity. We discuss M(atrix) theory description of compactification moduli space, symmetry enhance- ment thereof as well as further toroidal compactifications.

hep-th↗

arXiv1998

Baryon Chiral Perturbation Theory in Partially Quenched Large-Nc QCD

Baryons of lower spin in partially quenched large-$N_c$ QCD are studied with particular emphasis to interpolation between standard unquenched and fully quenched limits. In large $N_c$ limit of partially quenched QCD, we calculate $Δm$, the chiral one-loop correction to baryon masses. We find that leading order contribution to $Δm$ is independent of number of ghost quarks introduced. For finite $N_c$, chiral correction $Δm$ does satisfy the Bernard--Golterman's third theorem and has no infared quenching singularity except for fully quenched limit. At large $N_c$ limit, however, we show that the third theorem is bypassed and nontrivial quenched chiral corrections do arise. In unquenched limit, we also show that standard chiral perturbation theory results are reproduced in which $η'$ loop contributions are explicitly taken into account.

hep-ph↗

arXiv1998

Quenched and Partially Quenched Chiral Perturbation Theory for Vector and Tensor Mesons

Quenched and partially quenched chiral perturbation theory for vector mesons is developed and is used to extract chiral loop correction to the $ρ$ meson mass. Connections to fully quenched and totally unquenched chiral perturbation theory results are discussed. It is also shown that (partially) quenched perturbation theory for tensor mesons can be formulated analogously, and the chiral corrections for tensor meson masses are directly proportional to their counterparts in the vector meson sector. Utilizing this observation and non-relativistic quark model, we point out that mass difference $(m_{a_2} - {3 \over 2} m_ρ)$ is ``quenching-insensitive'' in large-$N_c$ limit. This quantity may be used for normalization of mass scale in lattice QCD calculations.

hep-ph↗

arXiv1998

Wilson-Polyakov Loop at Finite Temperature in Large N Gauge Theory and Anti-de Sitter Supergravity

Aspects of d=4, N=4 superconformal U(N) gauge theory are studied at finite temperature. Utilizing dual description of large $N$ and strong coupling limit via Type IIB string theory compactification on Schwarzschild anti-de Sitter spacetime, we study correlations of Wilson-Polyakov loops and heavy quark potential thereof. We find that the heavy quark potential is Coulomb-like and has a finite range, as expected for gauge theory in high temperature, deconfinement phase. The potential exhibits finite temperature scaling consistent with underlying conformal invariance. We also study isolated heavy quark on probe D3-brane world-volume and find supporting evidence that near extremal D3-branes are located at Schwarzschild horizon.

hep-th↗

arXiv1997

BPS Dynamics of Triple (p,q) String Junction

We study dynamics of triple junction of (p,q) strings in Type IIB string theory. We probe tension and mass density of (p,q) strings by studying harmonic fluctuations of the triple junction. We show that they agree perfectly with BPS formula provided suitable geometric interpretation of the junction is given. We provide a precise statement of BPS limit and force-balance property. At weak coupling and sufficiently dense limit, we argue that (p,q)-string embedded in string network is a `wiggly string', whose low-energy dynamics can be described via renormalization group evolved, smooth effective non-relativistic string. We also suggest the possibility that, upon Type IIB strings are promoted to M-theory membrane, there can exist `evanescent' bound-states at triple junction in the continuum.

hep-th↗

arXiv1997

M(atrix) Theory on the Negative Light-Front

M(atrix) theory defines light-front description of M-theory boosted along positive direction of eleventh, M-coordinate. Rank of M(atrix) gauge group is directly related to M-momentum $P_{11} = N / R_{11}$ or, equivalently, to total number of D0-partons. Alternatively, M-theory may be boosted along opposite direction of M-coordinate, for which the theory consists only of anti-D0 partons. In M(atrix) theory description, we interpret this as analytic continuation of dimension of the gauge group: $U(-N) \sim U(N)$, $SO(-2N) \sim USp(2N)$ and $USp(-2N) \sim SO(2N)$. We check these reciprocity relations explicitly for uncompactified, heterotic, and CHL M(atrix) theories as well as effective M(atrix) gauge theories of $T_5/Z_2$ and $T_9/Z_2$ compactifications. In all cases, we show that absence of parity, gauge and supersymmetry anomalies require introduction of a twisted sector with negative numbers of matter multiplets. They are interpreted as massless open string excitations connected to anti-D-brane background.

hep-th↗