M-brane Configurations Research Articles

PhreMology: calibrating M-branes

The relevance of calibrations, and `generalized' calibrations, to supersymmetric M-brane configurations and their associated field theories is reviewed, with emphasis on applications to domain walls and domain wall junctions of D = 4,N = 1 supersymmetric field theories.

M-theory realization of a an N = 1 supersymmetric chiral gauge theory in four dimensions

We study the M5-brane configuration of the chiral gauge theory whose type IIA brane configuration with an orientifold 6-plane (06) is studied by various authors. Much of thepaper is devoted to studying the related M-theory picture of SO/ Sp gauge theory with fundamental flavors realized in a type IIA setup with the 06-plane. The Higgs branch of N = 2 SO/ Sp gauge theory is studied and the curve corresponding to the rotated brane configuration is presented. In the chiral gauge theory, the middle NS′5-brane on top of the 06-plane is realized as a detached rational curve in M-theory. Depending on the location of the rational curve in the x 7 direction, the same curve plus the rational curve can be interpreted as describing the Coulomb branch of SU(2 N c ) chiral gauge theory, SO(2 N c )/ Sp( N c ) gauge theory with N f /( N f+4 ) fundamental hypermultiplets. Various consistency checks for this proposal are made. By introducing two more rational curves corresponding to NS′5-branes one can produce a non-trivial fixed point which mediates chiral-non-chiral transition.

Space-times of boosted p-branes, and CFT in infinite-momentum frame

We study the space-times of the near-horizon regions in D3-brane, M2-brane and M5-brane configurations, in cases where there is a pp-wave propagating along a direction in the world-volume. While non-extremal configurations of this kind locally have the same Carter-Novotný-Horský-type metrics as those without the wave, taking the BPS limit results instead in Kaigorodov-type metrics, which are homogeneous, but preserve 1 4 of the supersymmetry, and have global and local structures that are quite different from the corresponding anti-de Sitter space-times associated with solutions where there is no pp-wave. We show that the momentum density of the system is non-vanishing and held fixed under the gravity decoupling limit. In view of the AdS/CFT correspondence, M-theory and type IIB theory in the near-horizon region of these boosted BPS-configurations specifies the corresponding CFT on the boundary in an infinitely boosted frame with constant momentum density. We model the microstates of such boosted configurations (which account for the microscopic counting of near-extremal black holes in D = 7, D = 9 and D = 6 by those of a boosted dilute massless gas in a d = 4, d = 3 and d = 6 space-time respectively. Thus we obtain a simple description for the entropy of 2-charge black holes in D = 7, 9 and 6 dimensions. The paper includes constructions of generalisations of the Kaigorodov and Carter-Novotný-Horský metrics in arbitrary space-time dimensions, and an investigation of their properties.

Aspects of confinement and screening in M-theory

Confinement and screening are investigated in SUSY gauge theories, realized by an M5-brane configuration, extending an approach applied previously to N = 1 SYM theory, to other models. The electric flux tubes are identified as M2-branes ending on the M5-branes and the conserved charge they carry is identified as a topological property. The group of charges carried by the flux tubes is calculated and the results agree in all cases considered with the field-theoretical expectations. In particular, whenever the dynamical matter is expected to screen the confining force, this is reproduced correctly in the M-theory realization.

M-branes and their interactions in the static matrix model

Different BPS M-brane configurations including single and two parallel M p-branes ( p even) and M5-branes are introduced as the classical solutions of the recently proposed Static Matrix Model. Also the long-range interactions of two relatively rotated M p-branes (one and two angles) and M p-brane-anti-M p-brane are calculated. The results are in agreement with 11-dimensional supergravity results.

Supersymmetry enhancement ofD−p-branes andM-branes

We examine the supersymmetry of classical D-brane and M-brane configurations and explain the dependence of Killing spinors on coordinates. We find that one half supersymmetry is broken in the bulk and that supersymmetry near the D-brane horizon is restored for $p\leq 3$, for solutions in the stringy frame, but only for $p=3$ in the10d canonical frame. We study the enhancement for the case of four intersecting D-3-branes in 10 dimensions and the implication of this for the size of the infinite throat of the near horizon geometry in non-compactified theory. We found some indications of universality of near horizon geometries of various intersecting brane configurations.

M-theory superalgebra from the M-5-brane

The algebra of Noether supercharges of the M-5-brane effective action is shown to include both 2-form and 5-form central charges. Surprisingly, only the 5-form charge is entirely due to the Wess-Zumino term because the `naive' algebra is the M-2-brane supertranslation algebra. The full structure of central charges is shown to be directly related to the projector arising in the proof of $\kappa$-symmetry of the M-5-brane action. It is also shown to allow `mixed' M-brane configurations preserving 1/2 supersymmetry that include the (non-marginal) M-2-brane/M-5-brane `bound state' as a special case.

Composite BPS configurations of p-branes in 10 and 11 dimensions

We give an overview of various composite BPS configurations of string theory and M-theory p-branes represented as classical supergravity solutions. Type II string backgrounds can be obtained by S- and T-dualities from the NS - NS configurations corresponding to exact conformal sigma-models. The single-centre solutions can also be generated from the Schwarzschild solution by applying a sequence of boosts, `smearings' in some number of dimensions, dualities and taking the extremal limit. The basic `marginal' backgrounds representing threshold BPS bound states of branes are parametrized by a number of independent harmonic functions, one for each brane. `Non-marginal' BPS configurations in D = 10 can be constructed from the marginal ones using U-duality and thus are parametrized, in addition to harmonic functions, by a finite number of O(d,d) and SL(2,R) `angles'. Some of them can be viewed as dimensional reductions of coordinate-transformed (boosted or rotated) marginal configurations of M-branes. We present a new more general class of configurations in which some of the branes or their intersection spaces are localized on other branes. In particular, we find the supergravity background describing the type II BPS configuration of a 3-brane, RR 5-brane and NS - NS 5-brane, and a related `localized' 2-5-5 D = 11 solution. We also consider the classical action for a 3-brane probe moving in such type IIB backgrounds and determine the structure of the corresponding moduli space metrics.

Rotating intersecting M-branes

We present intersecting p-brane solutions of eleven-dimensional supergravity (M-branes) which upon toroidal compactification reduce to non-extreme rotating black holes. We identify harmonic functions, associated with each M-brane, and non-extremality functions, specifying a deviation from the BPS limit. These functions are modified due to the angular momentum parameters, which specify the rotation along the transverse directions of the M-branes. We spell out the intersection rules for the eleven-dimensional space-time metric for intersecting (up to three) rotating M-brane configurations (and a boost along the common intersecting direction).