Dyonic membranes (original) (raw)

Theoretical and Phenomenological Aspects of Superstring Theories

1998

Introduction CHAPTER 2 2 Compactification on Orbifolds 2.1 Toroidal Compactifications 2.2 General Theory of Orbifold Compactifications 2.3 Duality Symmetries CHAPTER 3 3 Aspects of Threshold Corrections to Low Energy Effective string Theories compactified on Orbifolds 1 where the invariant integral is given by ds 2 = −g µν (x)dx µ dx ν. 2 For n = 0 we have the point particle, for n = 1 we have the string, while for n = 2 we have the membrane and so on. . .. 3 See the footnote following 3.31. 4 Unoriented open and closed strings with N = 1 supersymmetry. 5 The ten dimensional N = 1 supergravity coupled to matter has anomalies coming from hegagon diagrams.

Self-dual strings and N = 2 supersymmetric field theory

Nuclear Physics B, 1996

We show how the Riemann surface of N = 2 Yang-Mills eld theory arises in type II string compactications on Calabi-Yau threefolds. The relevant local geometry is given by brations of ALE spaces. The 3-branes that give rise to BPS multiplets in the string descend to self-dual strings on the Riemann surface, with tension determined by a canonically xed Seiberg-Witten dierential . This gives, eectively, a dual formulation of Yang-Mills theory in which gauge bosons and monopoles are treated on equal footing, and represents the rigid analog of type II-heterotic string duality. The existence of BPS states is essentially reduced to a geodesic problem on the Riemann surface with metric jj 2 . This allows us, in particular, to easily determine the spectrum of stable BPS states in eld theory.

An SL(2, Z) multiplet of black holes in D=4 type II superstring theory

Physics Letters B, 1998

It is well-known that the conjectured SL(2, Z) invariance of type IIB string theory in ten dimensions also persists in lower dimensions when the theory is compactified on tori. By making use of this recent observation, we construct an infinite family of magnetically charged black hole solutions of type II superstring theory in four space-time dimensions. These solutions are characterized by two relatively prime integers corresponding to the magnetic charges associated with the two gauge fields (from NS-NS and R-R sectors) of the theory and form an SL(2, Z) multiplet. In the extremal limit these solutions are stable as they are prevented from decaying into black holes of lower masses by a 'mass gap' equation.

An Sl(2, Z) multiplet of nine-dimensional type II supergravity theories

Nuclear Physics B, 1999

We show that only by performing generalized dimensional reductions all possible brane configurations are taken into account and one gets the complete lowerdimensional theory. We apply this idea to the reduction of type IIB supergravity in an SL(2, R)-covariant way and establish T duality for the type II superstring effective action in the context of generalized dimensional reduction giving the corresponding generalized Buscher's T duality rules.

On S DUALITY OF TOROIDALLY COMPACTIFIED TYPE IIB STRING EFFECTIVE ACTION

International Journal of Modern Physics A, 1998

It has been shown recently that the toroidally compactified type IIB string effective action possesses an SL (2, R) invariance as a consequence of the corresponding symmetry in ten dimensions when the self-dual five-form field strength is set to zero. By working in the string frame we clarify how a Z2 subgroup of this SL (2, R) group responsible for producing the strong–weak coupling duality in the ten-dimensional theory produces the same symmetry for the reduced theory. In the absence of the full covariant action of type IIB supergravity theory, we show that the T-dual version of type IIA string effective action (including the R–R terms) in D = 9 also possesses the SL (2, R) invariance, indicating that this symmetry is present for the full type IIB string effective action compactified on the torus. By making use of this symmetry we briefly indicate how, from the known classical solutions of string theory, an SL (2, Z) multiplet of solutions can be constructed. This, in turn, provid...

Two-dimensional dilaton gravity black hole solution for N = 2 superstring theory

Physics Letters B, 1994

We show that N = 8 self-dual supergravity theory, which is the consistent background for N = 2 closed superstring theory in 2 + 2-dimensions, can accommodate the recently discovered two-dimensional dilaton gravity black hole solution, via appropriate dimensional reductions and truncations. Interestingly, the usual dilaton eld in this set of solutions emerges from the scalar eld in the 70-dimensional representation of an intrinsic global SO(8) group. We also give a set of exact solutions, which can be interpreted as the dilaton eld on Eguchi-Hanson gravitational instanton background, realized in an N = 1 self-dual supergravity theory. This suggests that the N = 2 superstring has a close (even closer) relationship with the two-dimensional black hole solution, which w as originally developed in the context of bosonic string and N = 1 superstring. Our result also provides supporting evidence for the conjecture that the N = 2 superstring theory is the \master theory" of supersymmetric integrable systems in lower-dimensions.

Flux compactifications of Type II string theories under non-perturbative dualities

2010

We consider string vacua formed by compactifying Type II string theories on toroidal orbifolds and generalised Calabi-Yau manifolds and their transformations under a set of non-perturbative dualities. The dualities are the Type IIA-IIB exchanging T duality, the self-symmetry of Type IIB S duality, the non-trivial combination of the two, U duality, and the generalisation of T duality to include Calabi-Yaus, mirror symmetry. The requirement of the effective theory superpotential being invariant under these dualities is used to justify additional fluxes which do not descend via compactification from the ten dimensional action, which form an N = 2 theory. Their non-geometric structures, Bianchi constraints and tadpoles are determined and then classified in terms of modular S duality induced multiplets. The Z2 Z2 orientifold is used as an explicit example of the general methods, with N = 1 Type IIB non-geometric vacua which possess T and S duality invariance also constructed. These are t...

N = 2 heterotic superstring and its dual theory in five dimensions

Nuclear Physics B, 1996

We study quantum effects in five dimensions in heterotic superstring theory compactified on K 3 × S 1 and analyze the conjecture that its dual effective theory is eleven-dimensional supergravity compactified on a Calabi-Yau threefold. This theory is also equivalent to type II superstring theory compactified on the same Calabi-Yau manifold, in an appropriate large volume limit. In this limit the conifold singularity disappears and is replaced by a singularity associated to enhanced gauge symmetries, as naïvely expected from the heterotic description. Furthermore, we exhibit the existence of additional massless states which appear in the strong coupling regime of the heterotic theory and are related to a different type of singular points on Calabi-Yau threefolds.

Type-II superstrings and new spacetime superalgebras

Physical Review D, 1999

We present a geometric formulation of type-IIA and-IIB superstring theories in which the Wess-Zumino term is second order in the supersymmetric currents. The currents are constructed using supergroup manifolds corresponding to superalgebras: the IIA superalgebra derived from M-algebra and the IIB superalgebra obtained by a T-duality transformation of the IIA superalgebra. We find that a slight modification of the IIB superalgebra is needed to describe D-string theories, in which the U(1) gauge field on the worldsheet is explicitly constructed in terms of D-string charges. A unification of the superalgebras in a (10 + 1)-dimensional N = 2 superalgebra is discussed too.

SL(2, Z) multiplets of type II superstrings in D<10

Physics Letters B, 1998

It has been shown recently that the toroidally compactified type IIB string effective action possesses an SL(2, R) invariance. Using this symmetry we construct an infinite family of macroscopic string-like solutions permuted by SL(2, Z) group for type II superstrings in 4 ≤ D < 10. These solutions, which formally look very similar to the corresponding solutions in D = 10, are characterized by two relatively prime integers corresponding to the 'electric' charges associated with the two antisymmetric tensor fields of the strings. Stability of these solutions is discussed briefly in the light of charge conservation and the tension gap equation.