Searcharxiv⌕ Search

arXiv subjects

N. D. Lambert

Publications and source records attributed to N. D. Lambert.

31 records · Page 2Linked to original sources
arXiv1998

Gauge Fields and M-Fivebrane Dynamics

In this paper we obtain both the vector and scalar equations of motion of an M-fivebrane in the presence of threebrane solitons. The resulting equations of motion are precisely those obtained from the Seiberg-Witten low energy effective action for N=2 Yang-Mills, including all quantum corrections. This analysis extends the work of a previous paper which derived the scalar equations of motion but not in detail the vector equations. We also discuss some features of an infinite number of higher derivative terms predicted by M theory.

hep-th↗
arXiv1998

D-brane Bound States and the Generalised ADHM Construction

We discuss the sigma model description of a D-string bound to k D-fivebranes in type I string theory. The effective theory is an (0,4) supersymmetric hyper-Kahler with torsion sigma model on the moduli space of Sp(k) instantons on R^4. Upon toroidal compactification to five dimensions the model is related to the type II picture where the target space is a symmetric product of K3's.

hep-th↗
arXiv1997

The Threebrane Soliton of the M-Fivebrane

We discuss the supersymmetry algebra of the M theory fivebrane and obtain a new threebrane soliton preserving half of the six-dimensional supersymmetry. This solution is dimensionally reduced to various D-p-branes.

hep-th↗
arXiv1997

The Self-Dual String Soliton

We obtain a BPS soliton of the M theory fivebrane's equations of motion representing a supersymmetric self-dual string. The resulting solution is then dimensionally reduced and used to obtain 0-brane and (p-2)-brane solitons on D-p-branes.

hep-th↗
arXiv1997

A New Massive Type IIA Supergravity From Compactification

We consider the most general form for eleven dimensional supersymmetry compatible with on-shell superfields. This allows for the introduction of a conformal Spin(1,10) connection. In eleven dimensional Minkowski space this modification is trivial and can be removed by a field redefinition, however, upon compactification on S^1 it is possible to introduce a non-trivial `Wilson line'. The resulting ten dimensional supergravity has massive 1-form and 3-form potentials and a cosmological constant. This theory does not possess a supersymmetric eightbrane soliton but it does admit a supersymmetric non-static cosmological solution.

hep-th↗
arXiv1997

Potentials and T-duality

We discuss the application of T-duality to massive supersymmetric sigma models. In particular (1,1) supersymmetric models with off-shell central charges reveal an interesting structure. The T-duality transformations of the BPS states of these theories are also discussed and an explicit example of Q-kinks is given.

hep-th↗
arXiv1996

Heterotic p-branes from Massive Sigma Models

We explicitly construct massive (0,4) supersymmetric ADHM sigma models which have heterotic p-brane solitons as their conformal fixed points. These yield the familiar gauge 5-brane and a new 1-brane solution which preserve 1/2 and 1/4 of the spacetime supersymmetry respectively. We also discuss an analogous construction for the type II NS-NS p-branes using (4,4) supersymmetric models.

hep-th↗
arXiv1996

Dyonic p-branes from self-dual (p+1)-branes

The `electromagnetic' $Sl(2;\bZ)$ duality group in spacetime dimension $D=4k$ can be given a Kaluza-Klein interpretation in $D=4k+2$ as the modular group of a compactifying torus. We show how dyonic $2(k-1)$-branes in $D=4k$ can be interpreted as self-dual $(2k-1)$-branes in $D=4k+2$ wound around the homology cycles of the torus. In particular, dyons of the D=4 N=4 heterotic string theory are interpreted as winding modes of a D=6 self-dual string, while D=8 dyonic membranes are interpreted as wound 3-branes of D=10 IIB superstring theory. We also discuss the T-dual IIA interpretations of D=8 dyonic membranes.

hep-th↗
arXiv1995

Quantizing the (0,4) Supersymmetric ADHM Sigma Model

We discuss the quantization of the ADHM sigma model. We show that the only quantum contributions to the effective theory come from the chiral anomalies and compute the first and second order terms. Finally the limit of vanishing instanton size is discussed.

hep-th↗
arXiv1995

Dyonic Membranes

We present dyonic multi-membrane solutions of the N=2 D=8 supergravity theory that serves as the effective field theory of the $T^2$-compactified type II superstring theory. The `electric' charge is fractional for generic asymptotic values of an axion field, as for D=4 dyons. These membrane solutions are supersymmetric, saturate a Bogomolnyi bound, fill out orbits of an $Sl(2;\Z)$ subgroup of the type II D=8 T-duality group, and are non-singular when considered as solutions of $T^3$-compactified D=11 supergravity. On $K_3$ compactification to D=4, the conjectured type II/heterotic equivalence allows the $Sl(2;\Z)$ group to be reinterpreted as the S-duality group of the toroidally compactified heterotic string and the dyonic membranes wrapped around homology two-cycles of $K_3$ as S-duals of perturbative heterotic string states.

hep-th↗
arXiv1995

Two Loop Renormalization of Massive (p,q) Supersymmetric Sigma Models

We calculate the beta-functions of the general massive (p,q) supersymmetric sigma model to two loop order using (1,0) superfields. The conditions for finiteness are discussed in relation to (p,q) supersymmetry. We also calculate the effective potential using component fields to one loop order and consider the possibility of perturbative breaking of supersymmetry. The effect of one loop finite local counter terms and the ultra-violet behaviour of the off-shell (p,q) models to all orders in perturbation theory are also addressed.

hep-th↗
arXiv1995

Topological Massive Sigma Models

In this paper we construct topological sigma models which include a potential and are related to twisted massive supersymmetric sigma models. Contrary to a previous construction these models have no central charge and do not require the manifold to admit a Killing vector. We use the topological massive sigma model constructed here to simplify the calculation of the observables. Lastly it is noted that this model can be viewed as interpolating between topological massless sigma models and topological Landau-Ginzburg models.

hep-th↗