Kentaroh Yoshida

Families of IIB duals for nonrelativistic CFTs

We show that the recent string theory embedding of a spacetime with nonrelativistic Schrodinger symmetry can be generalised to a twenty one dimensional family of solutions with that symmetry. Our solutions include IIB backgrounds with no three form flux turned on, and arise as near horizon limits of branewave spacetimes. We show that there is a hypersurface in the space of these theories where an instability appears in the gravitational description, indicating a phase transition in the nonrelativistic field theory dual. We also present simple embeddings of duals for nonrelativistic critical points where the dynamical critical exponent can take many values z ≠ 2.

Super Schrödinger algebra in AdS/CFT

We discuss (extended) super-Schrodinger algebras obtained as subalgebras of the superconformal algebra psu(2,2∣4). The Schrodinger algebra with two spatial dimensions can be embedded into so(4,2). In the superconformal case the embedded algebra may be enhanced to the so-called super-Schrodinger algebra. In fact, we find an extended super-Schrodinger subalgebra of psu(2,2∣4). It contains 24 supercharges (i.e., 3/4 of the original supersymmetries) and the generators of so(6), as well as the generators of the original Schrodinger algebra. In particular, the 24 supercharges come from 16 rigid supersymmetries and half of 16 superconformal ones. Moreover, this superalgebra contains a smaller super-Schrodinger subalgebra, which is a supersymmetric extension of the original Schrodinger algebra and so(6) by eight supercharges (half of 16 rigid supersymmetries). It is still a subalgebra even if there are no so(6) generators. We also discuss super-Schrodinger subalgebras of the superconformal algebras, osp(8∣4) and ...

More super Schrodinger algebras from psu(2,2|4)

We discuss super Schrodinger algebras with less supercharges from =4 superconformal algebra psu(2,2|4). Firstly =2 and =1 superconformal algebras are constructed from the psu(2,2|4) via projection operators. Then a super Schrodinger subalgebra is found from each of them. The one obtained from =2 has 12 supercharges with su(2)2 × u(1) and the other from =1 has 6 supercharges with u(1)3. By construction, those are still subalgebras of psu(2,2|4). Another super Schrodinger algebra, which preserves 6 supercharges with a single u(1) symmetry, is also obtained from =1 superconformal algebra su(2,2|1). In particular, it coincides with the symmetry of =2 non-relativistic Chern-Simons matter system in three dimensions.

Non-relativistic M2-brane gauge theory and new superconformal algebra

We study non-relativistic limits of the = 6 Chern-Simons-Matter theory that arises as a low-energy limit of the M2-brane gauge theory with background flux. The model admits several different non-relativistic limits and we find that the maximal supersymmetry we construct has 14 components of supercharges, which is a novel example of non-relativistic superconformal algebra in (1+2) dimension. We also investigate the other limits that realize less supersymmetries.

A semiclassical string description of Wilson loop with local operators

Abstract We discuss a semiclassical string description to circular Wilson loops without/with local operator insertions. Type IIB string theory on AdS 5 × S 5 is expanded around the corresponding classical solutions with respect to fluctuations and semiclassical quadratic actions are computed. Then the dual corresponding operators describing the fluctuations are discussed from the point of view of a small deformation of the Wilson loops. The result gives new evidence for AdS/CFT correspondence.

Higher Loop Bethe Ansatz for Open Spin-Chains in AdS/CFT

We propose a perturbative asymptotic Bethe ansatz (PABA) for open spin-chain systems whose Hamiltonians are given by matrices of anomalous dimension for composite operators, and apply it to two types of composite operators related to two different brane configurations. One is an AdS4 ? S2-brane in the bulk AdS5 ? S5 which gives rise to a defect conformal field theory (dCFT) in the dual field theory, and the other is a giant graviton system with an open string excitation. In both cases, excitations on open strings attaching to D-branes (a D5-brane for the dCFT case, and a spherical D3-brane for the giant graviton case) can be represented by magnon states in the spin-chains with appropriate boundary conditions, in which informations of the D-branes are encoded. We concentrate on single-magnon problems, and explain how to calculate boundary S-matrices via the PABA technique. We also discuss the energy spectrum in the BMN limit.

Non-relativistic AdS branes and Newton-Hooke superalgebra

We examine a non-relativistic limit of D-branes in AdS5 × S5 and M-branes in AdS4/7 × S7/4. First, Newton-Hooke superalgebras for the AdS branes are derived from AdS × S superalgebras as Inonu-Wigner contractions. It is shown that the directions along which the AdS-brane worldvolume extends are restricted by requiring that the isometry on the AdS-brane worldvolume and the Lorentz symmetry in the transverse space naturally extend to the super-isometry. We also derive Newton-Hooke superalgebras for pp-wave branes and show that the directions along which a brane worldvolume extends are restricted. Then the Wess-Zumino terms of the AdS branes are derived by using the Chevalley-Eilenberg cohomology on the super-AdS × S algebra, and the non-relativistic limit of the AdS-brane actions is considered. We show that the consistent limit is possible for the following branes: Dp (even,even) for p = 1 mod 4 and Dp (odd,odd) for p = 3 mod 4 in AdS5 × S5, and M2 (0,3), M2 (2,1), M5 (1,5) and M5 (3,3) in AdS4 × S7 and S4 × AdS7. We furthermore present non-relativistic actions for the AdS branes.

Open semiclassical strings and long defect operators in AdS / dCFT correspondence

We consider defect composite operators in a defect superconformal field theory obtained by inserting an AdS{sub 4}xS{sup 2}-brane in the AdS{sub 5}xS{sup 5} background. The one-loop dilatation operator for the scalar sector is represented by an integrable open spin chain. We give a description to construct coherent states for the open spin chain. Then, by evaluating the expectation value of the Hamiltonian with the coherent states in a long operator limit, a Landau-Lifshitz type of sigma model action is obtained. This action is also derived from the string action and hence we find a complete agreement in both super Yang-Mills and string sides. We see that an SO(3){sub H} pulsating string solution is included in the action and its energy completely agrees with the result calculated in a different method. In addition, we argue that our procedure would be applicable to other AdS-brane cases.

D-branes of covariant AdS superstrings

Abstract We consider D-branes of open superstrings in the AdS 5 × S 5 background. The possible configurations of D-branes preserving half of supersymmetries are classified by analyzing the κ -invariance of an open superstring in a covariant manner. We also revisit the classification of D-branes in the pp-wave background. It is shown that Penrose limits of the possible D-branes in the AdS 5 × S 5 give all of the D-branes in the pp-wave. In addition, a 1/4 supersymmetric D-string, which is related to the D-string preserving 8 dynamical supersymmetries in the pp-wave, is presented. We also discuss the relation between our result and the AdS branes in a brane probe analysis.

Open spinning strings and AdS/dCFT duality

We consider open spinning string solutions on an AdS4 ? S2-brane (D5-brane) in the bulk AdS5 ? S5 background. By taking account of the breaking of SO(6)R to SO(3)H ? SO(3)V due to the presence of the AdS-brane, the open rotating string ansatz is discussed. We construct the elliptic folded/circular open string solutions in the SU(2) and the SL(2) sectors, so that they satisfy the appropriate boundary conditions. On the other hand, in the SU(2) sector of the gauge theory, we compute the matrix of anomalous dimension of the defect operator, which turns out to be the hamiltonian of an open integrable spin chain. Then we consider the coordinate Bethe ansatz with arbitrary number of impurities, and compare the boundary condition of the Bethe wavefunction with that of the corresponding open string solution. We also discuss the Bethe ansatz for the open SL(2) spin chain with several supports from the string theory side. Then, in both SU(2) and SL(2) sectors, we analyze the Bethe equations in the thermodynamic limit and formulate the `doubling trick on the Riemann surface associated with the gauge theory.