8428441
Wound D-branes in Gepner models
We propose a new prescription of how to represent D-branes in Gepner models in more general homology classes than those in the previous constructions. The central role is played by a certain projection acting on the Recknagel–Schomerus boundary states. Consequently, the boundary states are in most cases no longer a sum of products of N=2 Ishibashi states, but nevertheless preserve spacetime supersymmetry and satisfy the Cardy condition. We demonstrate these in the (k=1)3 Gepner model in detail, and construct boundary states for D-branes wound around arbitrary rigid 1-cycles on the corresponding 2-torus. We also emphasize the necessity of some angle-dependent transformations in identifying a proper free-field realization for each brane tilted at an angle. In particular, this is essential for the Witten index to give the correct intersection numbers between the different D-branes.
119252236
New approach to solution generation usingSL(2,R)duality of a dimensionally reduced space in five-dimensional minimal supergravity and new black holes
The dimensional reduction of (the bosonic sector of) five-dimensional minimal supergravity to four dimensions leads to a theory with a massless axion and a dilaton coupled to gravity and two U(1) gauge fields (one of which has Chern-Simons coupling), whose field equations have SL(2,R)-invariance. Utilizing this SL(2,R)-duality, we provide a new formalism for solution generation. As an example, applying it to the Rasheed solution, which are known to describe dyonic rotating black holes (from the four-dimensional point of view) of five-dimensional pure gravity, we obtain rotating Kaluza-Klein black hole solutions in five-dimensional minimal supergravity. We also show that the solutions have six charges: mass, angular momentum, Kaluza-Klein electric/magnetic charges and electric/magnetic charges of the Maxwell field, four of which are related by a constraint.
12060817
MORE ON THE SIMILARITY BETWEEN D = 5 SIMPLE SUPERGRAVITY AND M THEORY
Abstract It has been known that D =5 simple supergravity resembles D =11 supergravity in many respects. We present their further resemblances in (1) the duality groups upon dimensional reduction, and (2) the worldsheet structure of the solitonic string of the D =5 supergravity. We show that the D =3, G 2(+2) / SO (4) (bosonic) nonlinear sigma model is obtained by using Freudenthal's construction in parallel to the derivation of the D =3, E 8(+8) / SO (16) sigma model from D =11 supergravity. The zero modes of the string solution with unbroken (4,0) supersymmetry consist of three (non-chiral) scalars, four Majorana-Weyl spinors of the same chirality and one chiral scalar, which suggests a duality to a certain six-dimensional chiral string theory. The worldsheet gravitational anomaly indicates a quantum correction to the Bianchi identity for the dualized two-form gauge field in the bulk just like the M5-brane case.
33408165
BPS saturation from null reduction
We show that any d-dimensional strictly stationary, asymptotically Minkowskian solution of a null reduction of (d + 1)-dimensional pure gravity must saturate the BPS bound if the spacetime admits another commuting Killing vector field so that the Kaluza-Klein vector field can be identified appropriately. We also argue that it is consistent with the field equations.
14833941
Gravitational corrections for supersymmetric gauge theories with flavors via matrix models
Abstract We study the gravitational corrections to the F-term in four-dimensional N = 1 U ( N ) gauge theories with flavors, using the Dijkgraaf–Vafa theory. We derive a compact formula for the annulus contribution in terms of the prime form on the matrix model curve. Remarkably, the full Tr R ∧ R correction can be reproduced as a special momentum sector of a single c = 1 CFT correlator, which closely resembles that in the bosonization of fermions on Riemann surfaces. The N = 2 limit of the torus contribution agrees with the multi-instanton calculations as well as the topological A-model result. The planar contributions, on the other hand, have no counterpart in the topological gauge theories, and we speculate about the origin of these terms.
120962173
Determinant formula and unitarity for the W3 algebra
Abstract The determinant formula for the W 3 algebra is presented. Using the graphical technique it is also shown that the possibly unitary representations are limited.
119301785
Five-year optical and near-infrared observations of the extremely slow nova V1280 Scorpii ,
We present optical (B, V, R c , I c and y) and near-infrared (J, H, and K s ) photometric and spectroscopic observations of a classical nova V 1280 Scorpii for five years from 2007 to 2011. Our photometric observations show a declining event in optical bands shortly after the maximum light, which took about 250 days to recover. This event was most probably caused by dust formation. The event was accompanied by a short (∼30 days) re-brightening episode (∼2.5 mag in V), which suggests that there had been some re-ignition of the surface nuclear burning. After 2008, the y band observations show a very long plateau at around y = 10.5 for more than 1000 days until April 2011 (∼1500 days after the maximum light). The nova had taken a very long time (∼50 months) to enter the nebular phase, according to a clear detection of both [O III] 4959 and 5007 and is still continuing to generate the wind caused by H-burning. This finding suggests that historically V1280 Sco is evolving at its slowest ever measured rate. The interval from the maximum light (2007 February 16) to the beginning of the nebular phase is longer than any previously known slow novae: V723 Cas (18 months), RR Pic (10 months), or HR Del (8 months). It suggests that the mass of a white dwarf in the V1280 Sco system might be 0.6 M ⊙ or lower. The distance, based on our measurements of the expansion velocity combined with the directly measured size of the dust shell, is estimated to be 1.1 ± 0.5 kpc.
118546306
Discovery of Multiple High-Velocity Narrow Circumstellar NaI D Lines in Nova V1280 Sco
We discovered multiple high-velocity (ranging from � 900 to � 650 km s � 1 ) and narrow (FWHM � 15 km s � 1 ) absorption components corresponding to both the D2 and the D1 lines of Na I on a high-dispersion spectrum of V1280 Sco, observed on 2009 May 9 (UT), 814 d after the V band maximum. Subsequent observations carried out on 2009 June and July confirmed at least 11 distinct absorption components in both systems. Some components had deepened during the two-month period while their HWHMs and wavelengths remained nearly constant. We suggest that these high-velocity components originated in cool clumpy gas clouds moving on the line-of-sight, produced during interactions between pre-existing cool circumstellar gas and high-velocity gas ejected in the nova explosion. The optical region spectrum of V1280 Sco in 2009 is dominated by the continuum radiation, and exhibits no forbidden line characterizing the nebular phase of typical novae. Permitted Fe II lines show doubly peaked emission profiles, and some strong Fe II lines are accompanied by a blue-shifted ( �� 255 km s � 1 ) absorption component. However, no high-velocity and narrow components corresponding to those of Na I could be detected in Fe II lines nor in the Balmer lines. The 255 km s � 1 low-velocity absorption component most probably originates in the wind from the nova.
117097765
Photometric and Spectroscopic Observations of V1280 Sco
Photometries of B, V, Rc, Ic, y, J, and Ks bands and low dispersion optical spectroscopic observations of Nova V1280 Sco, started soon after the outburst, are reported. We show that V1280 Sco is an Fe II nova and it is going through the historically slowest spectroscopic evolution. The rapid decline observed in the early phase was caused by formation of a dust shell. We estimate the abundances of CNO using the absorption lines on a spectrum at pre-maximum, and find over-abundances by [C/Fe] ~ 1.4, [N/Fe] > 2.0 and [O/Fe] ~ 1.1.