arXiv subjects

I. Y. Park

Publications and source records attributed to I. Y. Park.

At least 55 records · Page 3Linked to original sources

arXiv2012

$N^3$ entropy of M5 branes from dielectric effect

We observe that the $N^3$ entropy behavior of near-extermal M5 branes can be reproduced from SYM side with the role of Myers' terms. We start by generalizing the Klebanov-Tseytlin (KT) supergravity solution that displays the $N^3$ entropy behavior. The new feature of the general solution is visibility of the "internal" degrees of the M5 branes, i.e., the M0 branes and the M2 branes. With the rationale provided by the supergravity analysis, we consider a D0 brane quantum mechanical setup with Myers' terms. Using localization technique, we show that the leading $N^3$ behavior of the free energy comes from the "classical contribution" with the rest sub-leading.

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arXiv2012

Universality in all-order $α'$ corrections to BPS/non-BPS brane world volume theories

Knowledge of all-$α'$ higher derivative corrections to leading order BPS and non-BPS brane actions would serve in future endeavor of determining the complete form of the non-abelian BPS and tachyonic effective actions. In this paper, we note that there is a universality in the all-$α'$ order corrections to BPS and non-BPS branes. We compute amplitudes between one Ramond-Ramond $C$-field vertex operator and several SYM gauge/scalar vertex operators. Specifically, we evaluate in closed form string correlators of two-point amplitudes $\cal A^{Cϕ}$, $\cal A^{CA}$, a three-point amplitude $\cal A^{Cϕϕ}$ and a four-point amplitude $\cal A^{Cϕϕϕ}$. We carry out pole and contact term analysis. In particular we reproduce some of the contact terms and the infinite massless poles of $\cal A^{Cϕϕϕ}$ by SYM vertices obtained through the universality.

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arXiv2012

More on closed string induced higher derivative interactions on D-branes

In our continued efforts of matching full string computations with the corresponding effective field theory computations, we evaluate string theory correlators in closed forms. In particular, we consider a correlator between three SYM vertex operators and one Ramond-Ramond $C$-field vertex operator: $ $. We show that the infinite number of massless poles of this amplitude can be reproduced by the Born-Infeld action, the Wess-Zumino terms, and their higher derivative corrections. More specifically we find, up to an on-shell ambiguity, two scalar field and two gauge field couplings to all orders in $α'$ such that the infinite number of massless poles of the field theory amplitude exactly match the infinite number of massless poles of S-matrix elements of $ $. We comment on close intertwinedness of an open string and a closed string that must be behind the matching.

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arXiv2012

Near-Extremal Black Branes with n*3 Entropy Growth

In this paper, which is a companion to ArXiv:1204.2711[hep-th], we formulate a criterion for constructing 11D/10D maximal supergravity black-brane solutions with the near-extremal $S\sim n^3T^5$ entropy-temperature relation. We present explicit examples of such solutions with special attention paid to thermodynamics of black M-waves (KK-waves), intersecting/interpolating black branes with KK-waves, M2/M5 branes and their descents. We find the conditions on charges and numbers of branes in intersections, under which the dielectric effect of brane polarization becomes manifest on the supergravity side. We also briefly discuss the shear viscosity per entropy bound of M5 and D4 black branes within the AdS/CFT hydrodynamical limit.

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arXiv2012

SYM anomalous dimension from open string engineered curvature

In the full type IIB open superstring setup, we show that there exists a vertex operator, denoted by $V_L$, whose renormalization reproduces the same anomalous dimension matrix that was obtained by Minahan and Zarembo (MZ) in {\em JHEP} {\bf 0303}, 013 (2003). The vertex operator is a gauge singlet, and has the same SO(6) index structure as the operator used by MZ. To obtain the SYM anomalous dimensions, one of the key ingredients is the non-abelianization of the non-linear sigma model action in a D-brane background. In {\em Phys.\ Lett.} {\bf B 660}, 583 (2008), it was conjectured that quantum effects of open strings on a stack of D-branes should generate the curvature. Even though the conjecture had passed a few consistency checks, the role of the higher order curvature terms has remain mostly unobserved until now. By choosing a special form of the non-abelianized counter vertex, $V_G$, we show that the SYM result is reproduced. We comment on fermionic completion of $V_L$ and on how the special form of the non-abelian vertex $V_G$ may arise.

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arXiv2012

Fuzzy Kaluza-Klein induced M2's from a single M5

We propose an algorithmic procedure of obtaining multiple M2 brane dynamics starting with an action of a single M5 brane. The procedure involves a novel Kaluza-Klein reduction. First, the M5 brane action is truncated to keep a few leading terms in the derivative expansion. Then 3+3 splitting of dimensions is carried out. With expansion in terms of the S*2 spherical harmonics, the fields are associated with SU(N) (or its infinite extension) gauge algebra. We present an elaborate reduction procedure that leads to ABJM theory when the fuzzy spherical harmonics are replaced by SU(N) gauge generators.

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arXiv2011

Scattering of massive open strings in pure spinor

In {\em Phys.\ Lett.} {\bf B 660}, 583 (2008), it was proposed that the D-brane geometry could be produced by open string quantum effects. In an effort to verify the proposal, we consider scattering amplitudes involving {\em massive} open superstrings. The main goal of this paper is to set the ground for two-loop "renormalization" of an oriented open superstring on a D-brane and to strengthen our skill in the pure spinor formulation of a superstring, an effective tool for multi-loop string diagrams. We start by reviewing scattering amplitudes of massless states in the 2D component method of the NSR formulation. A few examples of massive string scattering are worked out. The NSR results are then reproduced in the pure spinor formulation. We compute the amplitudes using the massive vertex operator constructed by Berkovits and Chandia in {\em JHEP} {\bf 0208}, 040 (2002). We point out that it may be possible to discover new Riemann type identities involving Jacobi $\vartheta$-functions by comparing a NSR computation and the corresponding pure spinor computation.

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arXiv2010

Pure spinor computation towards open string three-loop

Using the recent results in the pure spinor formulation, we lay out a ground-work towards the full momentum space amplitudes of open superstrings at three-loop. After briefly reviewing the one-loop amplitude, we directly work out the two-loop and reproduce the result that was obtained by a symmetry argument. For the three-loop, first we use the two-loop regulator as a warm-up exercise. The result vanishes. We then employ the regulator that has been recently proposed by Aisaka and Berkovits (AB). It is noted that the terms in higher power in $\frac{1}{λ\barλ}$ that render the two-loop regulator disqualified for the three-loop do not contribute. This with a few other indications suggests a possibility that the AB regulator might also lead to a vanishing result. Nevertheless, we argue that it is possible to acquire the three-loop amplitude, and present a result that we anticipate to be the three-loop amplitude.

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arXiv2010

Vertex operator formulation of scattering around black hole

We propose a full-fledged open string framework that seems suited to study the black hole information paradox. We set up a configuration to compute the scattering amplitude of a IIB open string around a D5-brane. The D5-brane is situated at the origin of a transverse D3-brane. A string perturbation theory is employed where the geometry of the D5-brane is treated as a potential. We reason that the setup is capable of reconciling the unitary evolution of states and information loss that is measured by an observer on the D3 brane. With the configurations of these kinds, the information loss is an apparent phenomenon: it is just a manifestation of the fact that the D3-observer does not have access to the "hair" of the D5 black brane.

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arXiv2010

Geometric counter-vertex for open string scattering on D-branes

In arXiv:0801.0218 [hep-th] it was conjectured that quantum effects of open strings moving on D-branes generate the D-brane geometry through a counter-vertex operator. The conjecture has been checked at one-loop in arXiv:0806.3330 [hep-th]. Here we discuss the two-loop extension.

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arXiv2010

Semiclassical circular strings in AdS_5 and "long" gauge field strength operators

We consider circular strings rotating with equal spins S_1=S_2=S in two orthogonal planes in AdS_5 and suggest that they may be dual to "long" gauge theory operators built out of self-dual components of gauge field strength. As was found in hep-th/0404187, the one-loop anomalous dimensions of the such gauge-theory operators are described by an anti-ferromagnetic XXX_1 spin chain and scale linearly with length L>>1. We find that in the case of rigid rotating string both the classical energy E_0 and the 1-loop string correction E_1 depend linearly on the spin S (within the stability region of the solution). This supports the relation between the rigid rotating string and the gauge-theory operator corresponding to the maximal-spin (ferromagnetic) state of the XXX_1 spin chain. The energy of more general rotating and pulsating strings also happens to scale linearly with both the spin and the oscillation number. Such solutions should be dual to other lower-spin states of the spin chain, with the anti-ferromagnetic ground state presumably corresponding to the string pulsating in two planes with no rotation.

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arXiv2009

One loop scattering on D-branes

We analyze one loop scattering amplitudes of the massless states on a stack of D3-branes. We use the vertex operators that have been obtained in the direct open string analysis developed in arXiv:0708.3452. The method does not have the obstacle of the D9 computation which is associated with the appearance of an $\e$-tensor. The divergence structure is not the same as the D9 brane case. What makes the analysis deviate from the D9 brane case is that the momenta of the states have non-zero components only along the brane directions. We ponder on the possibility that the one-loop divergence may be canceled by adding additional vertex operators at the tree level. We anticipate that they will be "exponentiated" to the free string action, with the resulting action to constitute a non-linear sigma model of the D-brane/AdS geometry.

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arXiv2008

Open string engineering of D-brane geometry

One-loop scattering on a stack of D3 branes was considered in arXiv:0801.0218 [hep-th]. Divergence was found and its cancelation mechanism was proposed, wherein it was conjectured that the D-brane geometry be introduced in the form of counter vertex operators. Here we verify the conjecture at the first few leading orders in an expansion method that we call large-$r_0$ expansion. We comment on the relation with the Fischler-Susskind mechanism and discuss the implications of our result for AdS/CFT.

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arXiv2008

Scattering on D3-branes

In a direct open string approach we analyze scattering of massless states on a stack of D3-branes. First we construct vertex operators on the D-branes. The 4+6 splitting for the fermionic part is made possible by inserting appropriately defined projection operators. With the vertex operators constructed we compute various tree amplitudes. The results are then compared with the corresponding field theory computations of the $\N=4$ SYM with $\a'$-corrections: agreements are found. We comment on applications to AdS/CFT.

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arXiv2007

Toward getting finite results from N=4 SYM with alpha'-corrections

We take our first step toward getting finite results from the alpha'-corrected D=4 N=4 SYM theory with emphasis on the field theory techniques. Starting with the classical action of N=4 SYM with the leading alpha'-corrections, we examine new divergence at one loop due to the presence of the alpha'-terms. The new vertices do not introduce additional divergence to the propagators or to the three-point correlators. However they do introduce new divergence, e.g., to the scalar four-point function which should be canceled by extra counter-terms. We expect that the counter-terms will appear in the 1PI effective action that is obtained by considering the string annulus diagram. We work out the structure of the divergence and comment on an application to the anomalous dimension of the SYM operators in the context of AdS/CFT.

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arXiv2005

Spinning strings in AdS_5 x S^5: one-loop correction to energy in SL(2) sector

We consider a circular string with spin $S$ in $AdS_5$ wrapped around big circle of $S^5$ and carrying also momentum $J$. The corresponding N=4 SYM operator belongs to the SL(2) sector, i.e. has tr$(D^S Z^J)+...$ structure. The leading large $J$ term in its 1-loop anomalous dimension can be computed using Bethe ansatz for the SL(2) spin chain and was previously found to match the leading term in the classical string energy. The string solution is stable at large $J$, and the Lagrangian for string fluctuations has constant coefficients, so that the 1-loop string correction to the energy $E_1$ is given simply by the sum of characteristic frequencies. Curiously, we find that the leading term in the zero-mode part of $E_1$ is the same as a 1/J correction to the one-loop anomalous dimension on the gauge theory (spin chain) side that was found in hep-th/0410105. However, the contribution of non-zero string modes does not vanish. We also discuss the ``fast string'' expansion of the classical string action which coincides with the coherent state action of the SL(2) spin chain at the first order in $ł$, and extend this expansion to higher orders clarifying the role of the $S^5$ winding number.

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arXiv2004

On one-loop correction to energy of spinning strings in S^5

We revisit the computation (hep-th/0306130) of 1-loop AdS_5 x S^5 superstring sigma model correction to energy of a closed circular string rotating in S^5. The string is spinning around its center of mass with two equal angular momenta J_2=J_3 and its center of mass angular momentum is J_1. We revise the argument in hep-th/0306130 that the 1-loop correction is suppressed by 1/J factor (J= J_1 + 2 J_2 is the total SO(6) spin) relative to the classical term in the energy and use numerical methods to compute the leading 1-loop coefficient. The corresponding gauge theory result is known (hep-th/0405055) only in the J_1=0 limit when the string solution becomes unstable and thus the 1-loop shift of the energy formally contains an imaginary part. While the comparison with gauge theory may not be well-defined in this case, our numerical string theory value of the 1-loop coefficient seems to disagree with the gauge theory one. A plausible explanation should be (as in hep-th/0405001) in the different order of limits taken on the gauge theory and the string theory sides of the AdS/CFT duality.

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arXiv2004

Absorption of a Quantum in a D1/D5 System

In {\em Nucl. Phys.} B {\bf 615}, 285 (2001) [arXiv:hep-th/0107113], the wave equation for a minimally coupled scalar was studied in the geometry of a D1-D5 system with non-zero angular momentum. The probability for a quantum to enter the throat was computed by taking small a parameter $\g$ which is associated with the value of the angular momentum. In the leading order in $\g$, the result was found to agree with the dual CFT result. In this note, we report on an observation that there are corrections of higher order in $\g$. Our results should be useful for determining the higher order correction terms that the dual CFT needs in order to incorporate the presence of the `capped' geometry.

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