World-sheet Gauge Fields Research Articles

Light cone quantization and interactions of a new closed bosonic string inspired to [formula omitted] string

We quantize the bosonic part of the D1 string with closed boundary conditions on the light cone and we consider the U(1) worldsheet gauge field a dynamical variable. We compute also 3-Reggeon vertex by the overlapping technique. We find that the Fock space is the sum of sectors characterized by the momentum of the U(1) Wilson line and that these sectors do not interact among them. Each sector has exactly the same spectrum of the usual bosonic string when expressed in properly sector dependent rescaled variables. Rescaling is forced by factorization of the string amplitudes. We are also able to determine the relative string coupling constant of the different sectors. It follows a somewhat unexpected picture in which the effective action is always the same independently on the sector but string amplitudes are only the same when expressed in sector dependent rescaled variables.

THE GAUGING OF TWO-DIMENSIONAL BOSONIC SIGMA MODELS ON WORLD-SHEETS WITH DEFECTS

We extend our analysis of the gauging of rigid symmetries in bosonic two-dimensional sigma models with Wess–Zumino terms in the action to the case of world-sheets with defects. A structure that permits a non-anomalous coupling of such sigma models to world-sheet gauge fields of arbitrary topology is analyzed, together with obstructions to its existence, and the classification of its inequivalent choices.

Supersymmetric form of the string action in the presence of the gauge field

In this manuscript, we study the superstring theory with an Abelian worldsheet gauge field. The components of the gauge field appear as space and time coordinates. We call them “fictitious coordinates”. The worldsheet supersymmetry and the Poincaré symmetry of this model will be analyzed. The T-duality and quantization of the two fictitious coordinates are also obtained.

Perturbative super-Yang-Mills from the topologicalAdS5×S5sigma model

A topological sigma model based on the pure spinor formalism was recently proposed for the small radius limit of the AdS_5xS^5 superstring. Physical states in this model can be constructed by connecting holes on the worldsheet with Wilson lines of the worldsheet gauge field. The contribution of these states to the topological amplitude is claimed to reproduce the usual Feynman diagram expansion of gauge-invariant super-Yang-Mills correlation functions.

Infinitely many rigid symmetries of kappa-invariant D-string actions

We show that each rigid symmetry of a D-string action is contained in a family of infinitely many symmetries. In particular, kappa-invariant D-string actions have infinitely many supersymmetries. The result is not restricted to standard D-string actions, but holds for any two-dimensional action depending on an abelian world-sheet gauge field only via the field strength. It applies thus also to manifestly SL(2, Z) covariant D-string actions. Furthermore, it extends analogously to d-dimensional actions with ( d−1)-form gauge potentials, such as brane actions with dynamical tension.

Cohomological analysis of bosonic D-strings and 2d sigma models coupled to abelian gauge fields

We analyze completely the BRST cohomology on local functionals for two-dimensional sigma models coupled to abelian world-sheet gauge fields, including effective bosonic D-string models described by Born-Infeld actions. In particular we prove that the rigid symmetries of such models are exhausted by the solutions to generalized Killing vector equations which we have presented recently, and provide all the consistent first order deformations and candidate gauge anomalies of the models under study. For appropriate target space geometries we find nontrivial deformations both of the abelian gauge transformations and of the world-sheet diffeomorphisms, and antifield-dependent candidate anomalies for both types of symmetries separately, as well as mixed ones.

Canonical equivalence between super D-string and type IIB superstring

We show that the super D-string action is canonically equivalent to the type IIB superstring action with a world-sheet gauge field. Canonical transformation to the type IIB theory with dynamical tension is also constructed to establish the SL(2,Z) covariance beyond the semi-classical approximations.

On World-Sheet Gauge Fields in (1,0)- and (1,1)-Supersymmetric Gauge Theories

In this letter, component-field one-loop corrections are performed to integrate out matter fields in (1,0)- and (1,1)-supersymmetric gauge models. The results obtained are discussed in connection with central charge calculations.

Twistorlike type-II superstring with the heterotic (2,0) and (4,0) world sheet supersymmetry.

The twistorlike formulation of the type-II Green-Schwarz superstring with N=(2,0) and (4,0) heterotic world sheet supersymmetry is constructed. Both of the Virasoro constraints are solved with the help of twistors in dimensions D=4 and D=6. As in the case of N=(1,0) world sheet supersymmetry, considered earlier, no world sheet gauge fields enter the actions. On the component level the resulting Lagrangians are classically equivalent to the Green-Schwarz one.

GAUGING OF T-DUALITY INVARIANT WORLDSHEET STRING ACTIONS

T-duality invariant worldsheet string actions, recently written down by Schwarz and Sen, are coupled to the worldsheet gauge fields. It is shown that the integration of the dual coordinates gives the conventional, vector, axial and chiral, gauged string actions for the appropriate choice of the gauged isometries. Alternatively, the gauge field integration is shown to give a T-duality invariant action which matches with the corresponding results known earlier.

Gauging the Zamolodchikov [formula omitted]-algebra

A world-sheet action is presented whose constraint algebra is the Zamolodchikov W -algebra. It consists of a matter system, such as a free boson model or an SU (3) WZW model, coupled to world-sheet gauge fields of spin two and three which are Lagrange multipliers imposing the constraints. The classical symmetry group has an algebra with field-dependent structure constants. The possibility of a new kind of string theory based on the W -algebra instead of the Virasoro algebra is considered.

World-sheet gauge fields in superstrings

We investigate the introduction of world-sheet 2-dimensional gauge fields in a manner consistent with world-sheet supersymmetry. We obtain the effective string action resulting from the exact integration over the world-sheet gauge fields to show that it generally describes string models with spontaneous breaking of gauge symmetries with continuous breaking parameters. We examine the question of spacetime supersymmetry spontaneous breaking, and show that breaking with continuous, in particular arbitrarily small breaking parameters does not occur; only breaking for discrete values of parameters is possible.

Gauge fields on the world sheet: Strings with gauge- and supersymmetry breaking

It is shown that the introduction of two-dimensional gauge fields as dynamical degrees of freedom on the world sheet provides a general mechanism for obtaining spontaneous breakdown of spacetime gauge symmetries and supersymmetries in string theories. Other known methods of introducing symmetry breaking are seen to be included in the general world sheet gauge field formulation

Bose-Fermi equivalence of the two-dimensional torus for simply-laced groups

Bosonic and fermionic partition functions on the two-dimensional torus are explicitly calculated to establish a Bose-Fermi equivalence for each fundamental representation of every simple-laced group G. A one-to-one correspondence exists for bosons with momenta generated by the root lattice of G shifted by the element w k, where w k is a minimal weight of G, i.e. and element of the center of the covering group of G, and fermions with generalized boundary conditions ψ → (exp iθ k ) ψ (under rotation around the torus) where exp( iθ k ) is the same element of Z as is w k . The non-orthogonal weight lattices of G are converted into orthogonal lattices with constraints. It is shown that only for spin(2 N) can these constraints be written as projection operators, which correspond to sums over spin structure in fermion language. For SU( N), E 6 and E 7 the appropriate constraints are imposed by coupling the fermions to background U(1) world-sheet gauge fields which act as Lagrange multipliers, i.e. the equivalence is to constrained fermions. Explicit modular invariant partition functions are presented for closed strings compactified ti simply-laced groups associated to Kac-Moody algebras with central charge k = 1.