Boundary states in the Nappi-Witten model

We investigate D-branes in the Nappi-Witten model. Classically symmetric D-branes are classified by the (twisted) conjugacy classes of the Nappi-Witten group, which specify the geometry of the corresponding D-branes. Quantum description of the D-branes is given by boundary states, and we need one point functions of closed strings to construct the boundary states. We compute the one point functions solving conformal bootstrap constraints, and check that the classical limit of the boundary states reproduces the geometry of D-branes.Comment: 19 pages, no figure; minor changes, references adde

The adiabatic evolution of orbital parameters in the Kerr spacetime

We investigate the adiabatic orbital evolution of a point particle in the Kerr spacetime due to the emission of gravitational waves. In the case that the timescale of the orbital evolution is enough smaller than the typical timescale of orbits, the evolution of orbits is characterized by the change rates of three constants of motion, the energy $E$, the azimuthal angular momentum $L$, and the Carter constant $Q$. For $E$ and $L$, we can evaluate their change rates from the fluxes of the energy and the angular momentum at infinity and on the event horizon according to the balance argument. On the other hand, for the Carter constant, we cannot use the balance argument because we do not know the conserved current associated with it. %and the corresponding conservation law. Recently, Mino proposed a new method of evaluating the averaged change rate of the Carter constant by using the radiative field. In our previous paper we developed a simplified scheme for practical evaluation of the evolution of the Carter constant based on the Mino's proposal. In this paper we describe our scheme in more detail, and derive explicit analytic formulae for the change rates of the energy, the angular momentum and the Carter constant.Comment: 34 pages, no figur

A family of solvable non-rational conformal field theories

We find non-rational conformal field theories in two dimensions, which are solvable due to their correlators being related to correlators of Liouville theory. Their symmetry algebra consists of the dimension-two stress-energy tensor, and two dimension-one fields. The theories come in a family with two parameters: the central charge c and a complex number m. The special case m=0 corresponds to Liouville theory (plus two free bosons), and m=1 corresponds to the H3+ model. In the case m=2 we show that the correlators obey third-order differential equations, which are associated to a subsingular vector of the symmetry algebra.Comment: 14 pages, v2: role of subsingular vectors clarifie

Topological String on OSP(1|2)/U(1)

We propose an equivalence between topological string on OSP(1|2)/U(1) and \hat{c} \leq 1 superstring with N=1 world-sheet supersymmetry. We examine this by employing a free field representation of OSP(1|2) WZNW model and find an agreement on the spectrum. We also analyze this proposal at the level of scattering amplitudes by applying a map between correlation functions of OSP(1|2) WZNW model and those of N=1 Liouville theory.Comment: 25 pages, refereces adde

Liouville Field Theory on an Unoriented Surface

Liouville field theory on an unoriented surface is investigated, in particular, the one point function on a RP^2 is calculated. The constraint of the one point function is obtained by using the crossing symmetry of the two point function. There are many solutions of the constraint and we can choose one of them by considering the modular bootstrap.Comment: 13 pages, no figures, LaTeX, minor changes, equations in section 4 are correcte

Crosscap States for Orientifolds of Euclidean AdS_3

Crosscap states for orientifolds of Euclidean AdS_3 are constructed. We show that our crosscap states describe the same orientifolds which were obtained by the classical analysis. The spectral density of open strings in the system with orientifold can be read from the M"obius strip amplitudes and it is compared to that of the open strings stretched between branes and their mirrors. We also compute the Klein bottle amplitudes.Comment: 17 pages, LaTeX2e, v2: clarification and discussion added, v3: minor changes, to appear in JHE

Braiding and fusion properties of the Neveu-Schwarz super-conformal blocks

We construct, generalizing appropriately the method applied by J. Teschner in the case of the Virasoro conformal blocks, the braiding and fusion matrices of the Neveu-Schwarz super-conformal blocks. Their properties allow for an explicit verification of the bootstrap equation in the NS sector of the N=1 supersymmetric Liouville field theory.Comment: 41 pages, 3 eps figure

D-branes in PP-Waves and Massive Theories on Worldsheet with Boundary

We investigate the supersymmetric D-brane configurations in the pp-wave backgrounds proposed by Maldacena and Maoz. We study the surviving supersymmetry in a D-brane configuration from the worldvolume point of view. When we restrict ourselves to the background with N=(2,2) supersymmetry and no holomorphic Killing vector term, there are two types of supersymmetric D-branes: A-type and B-type. An A-type brane is wrapped on a special Lagrangian submanifold, and the imaginary part of the superpotential should be constant on its worldvolume. On the other hand, a B-type brane is wrapped on a complex submanifold, and the superpotential should be constant on its worldvolume. The results are almost consistent with the worldsheet theory in the lightcone gauge. The inclusion of gauge fields is also discussed and found BPS D-branes with the gauge field excitations. Furthermore, we consider the backgrounds with holomorphic Killing vector terms and N=(1,1) supersymmetric backgrounds.Comment: 27 pages, LaTeX, no figure. v2: typos corrected, comments added, references added. v3: typos corrected, comments added, references added. v4:typos correcte

Embedding massive flavor in ABJM

We add massive fundamental matter to the ABJM model by adding D6-branes wrapped asymptotically over RP3. We find two types of solutions at finite temperature, one that enters the black hole and one that ends before the black hole. We analyze the behavior of the free energy as a function of temperature, and find that the system exhibits a phase transition between the two types of solutions, similar to what happens in the D3-D7 system. We also analyze the meson spectrum in the model and find several massive scalar modes, again, quite like the D3-D7 system. We end with a calculation of the conductivities in the two phases.Comment: 26 pages, 6 figures; version published in JHE