68 research outputs found
On the construction of Chern-Simons terms in the presence of flux
We develop a method for relating the boundary effective action associated
with an orbifold of the D+1 dimensional theory of a p-form field to D
dimensional fluxed Chern-Simons type of terms. We apply the construction to
derive from twelve dimensions the Chern-Simons terms of the eleven dimensional
supergravity theory in the presence of flux.Comment: Minor corrections mad
Higher Spin Fields in Hyperspace. A Review
We will give an introduction to the so-called tensorial, matrix or hyperspace
approach to the description of massless higher-spin fields.Comment: 62 pages, invited review, references and clarifications added,
published versio
Universality of Gauge Thresholds in Non-Supersymmetric Heterotic Vacua
We compute one-loop threshold corrections to non-abelian gauge couplings in
four-dimensional heterotic vacua with spontaneously broken supersymmetry, obtained as Scherk-Schwarz reductions of six-dimensional
K3 compactifications. As expected, the gauge thresholds are no-longer BPS
protected, and receive contributions also from the excitations of the RNS
sector. Remarkably, the difference of thresholds for non-abelian gauge
couplings is BPS saturated and exhibits a universal behaviour independently of
the orbifold realisation of K3. Moreover, the thresholds and their difference
develop infra-red logarithmic singularities whenever charged BPS-like states,
originating from the twisted RNS sector, become massless at special loci in the
classical moduli space.Comment: 12 pages, corrected eqs. 3.19, 3.20 and 3.23 and an overall factor of
2 in all threshold
Higher Spins in Hyper-Superspace
We extend the results of arXiv:1401.1645 on the generalized conformal
Sp(2n)-structure of infinite multiplets of higher spin fields, formulated in
spaces with extra tensorial directions (hyperspaces), to the description of
OSp(1|2n)-invariant infinite-dimensional higher-spin supermultiplets formulated
in terms of scalar superfields on flat hyper-superspaces and on OSp(1|n)
supergroup manifolds. We find generalized superconformal transformations
relating the superfields and their equations of motion in flat hyper-superspace
with those on the OSp(1|n) supermanifold. We then use these transformations to
relate the two-, three- and four-point correlation functions of the scalar
superfields on flat hyperspace, derived by requiring the OSp(1|2n) invariance
of the correlators, to correlation functions on the OSp(1|n) group manifold. As
a byproduct, for the simplest particular case of a conventional N=1, D=3
superconformal theory of scalar superfields, we also derive correlation
functions of component fields of the scalar supermultiplet including those of
auxiliary fields.Comment: 25 pages, discussion in section 4.1 improved, references added;
subsection 2.4 and conclusions expanded, typos corrected, references added,
published versio
On Tensorial Spaces and BCFW Recursion Relations for Higher Spin Fields
In this short review we briefly consider two topics in the higher spin gauge
theory: the method of "tensorial (super) spaces" and application of BCFW
recursion relations to higher spin fields.Comment: 26 pages, Invited Review, discussion improved, references adde
Higher Spins in Hyperspace
We consider the Sp(2n) invariant formulation of higher spin fields on flat
and curved backgrounds of constant curvature.In this formulation an infinite
number of higher spin fields are packed into single scalar and spinor master
fields (hyperfields) propagating on extended spaces, to be called hyperspaces,
parametrized by tensorial coordinates.We show that the free field equations on
flat and AdS-like hyperspaces are related to each other by a generalized
conformal transformation of the scalar and spinor master fields. We compute the
four--point functions on a flat hyperspace for both scalar and spinor master
fields, thus extending the two-- and three--point function results of
arXiv:hep-th/0312244. Then using the generalized conformal transformation we
derive two--, three-- and four--point functions on AdS--like hyperspace from
the corresponding correlators on the flat hyperspace.Comment: 23 pages, typos corrected, references added. Published versio
Interacting Higher Spins and the High Energy Limit of the Bosonic String
In this note, we construct a BRST invariant cubic vertex for massless fields
of arbitrary mixed symmetry in flat space-time. The construction is based on
the vertex given in bosonic Open String Field Theory. The algebra of gauge
transformations is closed without any additional, higher than cubic, couplings
due to the presence of an infinite tower of massless fields. We briefly discuss
the generalization of this result to a curved space-time and other possible
implications.Comment: Published Version; typos corrected, references added; (v3) Some typos
corrected and a minor clarification about eq. (3.29
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