Supergravity null scissors and super-crosses

Self Cite

In this article we study D1-D3 (or D3) brane systems with generic constant electric and magnetic fluxes in IIB string theory. We work out all possible supersymmetric configurations and find out via T-duality all of them and corresponding supersymmetry conditions could be related to the supersymmetric intersecting D1-D1 pairs. And we do D1-D3 (or D3) open string quantization for a class of configurations. We find that there are many near massless states in NS sector for near-BPS configurations. Furthermore we calculate open string pair creation rate in generic nonsupersymmetric configurations. * Email:bchen01,liuxiaoerty@pku.edu.cn, D-branes and anti-D-branes are nonperturbative objects in string theory, carrying RR charges. A single BPS D-brane preserve half supersymmetries in flat spacetime. But if we put two different D-branes together, or let a D-brane be in a compact configuration, supersymmtry could be broken [1,2]. One typical example is a Dp-anti-Dp system which breaks all the supersymmetries. However, it turns out that when one turns on the background flux on the D-branes, the supersymmetries could be recovered. It is an interesting issue to look for these configurations. In [3], Mateos and Townsend found that if one turned on suitable gauge fluxes on tubular D2-brane, the system can be supersymmetric. This is so-called 'supertube'. The configuration could be taken as the blow-up of D-particles and has no net D2 brane charge. Effectively such system may be simplified to a D2-anti-D2 system with fluxes[4]. This discovery led to a lot of study of supersymmetric Dp-(anti)-Dp system with background fluxes [5,6,7,8]. In particular, it has been found even in Dp-anti-Dp system, the system could be supersymmetric if one turns on suitable fluxes.Another class of non-BPS brane configuration is Dp-Dq with p − p = 0 (mod 4). In particular, D0-D2 system is remarkable. The straightforward calculation of the D0-D2 open string spectrum shows that the ground state is tachyonic, which means that the system is unstable and non-BPS. However, it has been shown in [9] that D0-D2 system is actually dual to the (F1,D1) bound state. In fact, the underlying picture is that through tachyon condensation D0-D2 system settle down to a D0-D2 bound state, with D0 being dissolved into D2. Moreover, if one considers the gauge fluxes on D-brane, the story become more interesting. In D0-D2 system with magnetic field, in the zero-slop limit, there could exist an infinite tower of near massless states in the open string spectrum. On the other hand, the system could be studied in the framework of noncommutative gauge theory. In [10], the authors showed that in D0-D2 system with large magnetic field the D-particle could be taken as the soliton in (2+1)-dimensional noncommutative Yang-Mills theory. The large tower of near massless states corresponds to the fluctuations around the soliton solution. And due to the existence of the large magnetic field, the system is actually near-BPS, and the tachyon condensation could be very well studied, as sho...

Section: Conclusion and Discussionmentioning

confidence: 99%

Section: B T-dual Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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D1-D3 (or bar-D3) systems with fluxes

Chen¹,

Liu²

2008

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“…The angular position of a (n p (a) , n)-string, i.e., n multiples of a (p (a) , 1)-string, is independent of n. A special orthogonally intersecting case of a D-string and a F-string was discussed in the name of 'super cross' in Ref. [15]. The formula (8.7) is reminiscent of the S-dual transformation that leads to a (p, q)-string, being acted on a (1, 0)-string.…”

Section: Supersymmetric (P Q)-jackstrawsmentioning

confidence: 99%

Super jackstraws and super waterwheels

Cho¹

2007

We construct various new BPS states of D-branes preserving 8 supersymmetries. These include super Jackstraws (a bunch of scattered D-or (p, q)-strings preserving supersymmetries), and super waterwheels (a number of D2-branes intersecting at generic angles on parallel lines while preserving supersymmetries). Super D-Jackstraws are scattered in various dimensions but are dynamical with all their intersections following a common null direction. Meanwhile, super (p, q)-Jackstraws form a planar static configuration. We show that the SO(2) subgroup of SL(2, R), the group of classical S-duality transformations in IIB theory, can be used to generate this latter configuration of variously charged (p, q)-strings intersecting at various angles. The waterwheel configuration of D2-branes preserves 8 supersymmetries as long as the 'critical' Born-Infeld electric fields are along the common direction.

“…It was suggested in [17] (see also [18,19] for related work) that one may obtain insight into these issues by studying an open-string analogue of the null singularities. The relevant brane configurations are so-called null D-brane scissors -configurations of D-branes that intersect in a null hypersurface.…”

Section: Introductionmentioning

confidence: 99%

World-sheet duality for D-branes with travelling waves

Bachas¹,

Gaberdiel²

2004

We study D-branes with plane waves of arbitrary profiles as examples of timedependent backgrounds in string theory. We show how to reproduce the quantum mechanical (one-to-one) open-string S-matrix starting from the closed-string boundary state for the D-branes, thereby establishing the channel duality of this calculation. The required Wick rotation to a Lorentzian worldsheet singles out as 'prefered' time coordinate the open-string light-cone time.