Papers by Ignatios Antoniadis
Nuclear Physics B, 1995
We test the recently conjectured duality between N= 2 supersymmetric type II and heterotic string... more We test the recently conjectured duality between N= 2 supersymmetric type II and heterotic string models by analysing a class of higher-dimensional interactions in the respective low-energy Lagrangians. These are F-terms of the form FgW2g where W is the gravitational ...
Nuclear Physics B, 1997
We discuss type I-heterotic duality in four-dimensional models obtained as a Coulomb phase of the... more We discuss type I-heterotic duality in four-dimensional models obtained as a Coulomb phase of the six-dimensional U (16) orientifold model compactified on T 2 with arbitrary SU (16) Wilson lines. We show that Kähler potentials, gauge threshold corrections and the infinite tower of higher derivative F-terms agree in the limit that corresponds to weak coupling, large T 2 heterotic compactifications. On the type I side, all these quantities are completely determined by the spectrum of N =2 BPS states that originate from D=6 massless superstring modes.
Ganor, OJ, 25 Green, MB, 30 Hassan, SF, 93 Klein, M., 40 Lian, BH, 106
Nuclear Physics B, 2002
We study a class of type I string models with supersymmetry broken on the world-volume of some D-... more We study a class of type I string models with supersymmetry broken on the world-volume of some D-branes and vanishing tree-level potential. Despite the non-supersymmetric spectrum, supersymmetry is non-linearly realized on these D-branes, while it is spontaneously broken in the bulk by Scherk-Schwarz boundary conditions. These models can easily accommodate 3-branes with interesting gauge groups and chiral fermions. We also study the effective field theory and in particular we compute the four-fermion couplings of the localized Goldstino with the matter fermions on the brane.
Proceedings of Corfu Summer Institute on Elementary Particle Physics — PoS(corfu98), 1999
We obtain the non-perturbative effective potential for the dual five-dimensional N = 4 strings in... more We obtain the non-perturbative effective potential for the dual five-dimensional N = 4 strings in the context of finite-temperature regarded as a breaking of supersymmetry into four space-time dimensions. Using the properties of gauged N = 4 supergravity we derive the universal thermal effective potential describing all possible high-temperature instabilities of the known N = 4 superstrings. These strings undergo a high-temperature transition to a new phase in which five-branes condense. This phase is described in detail, using both the effective supergravity and non-critical string theory in six dimensions. In the new phase, supersymmetry is perturbatively restored but broken at the non-perturbative level.
We study off-shell rigid limits for the kinetic and scalar-potential terms of a single N = 2 hype... more We study off-shell rigid limits for the kinetic and scalar-potential terms of a single N = 2 hypermultiplet. In the kinetic term, these rigid limits establish relations between four-dimensional quaternion-Kähler and hyper-Kähler target spaces with symmetry. The scalar potential is obtained by gauging the graviphoton along an isometry of the quaternion-Kähler space. The rigid limits unveil two distinct cases. A rigid N = 2 theory on Minkowski or on AdS 4 spacetime, depending on whether the isometry is translational or rotational respectively. We apply these results to the quaternion-Kähler space with Heisenberg ⋉ U(1) isometry, which describes the universal hypermultiplet at type-II string one-loop.
We consider partial supersymmetry breaking in N = 2 supergravity coupled to a single vector and a... more We consider partial supersymmetry breaking in N = 2 supergravity coupled to a single vector and a single hypermultiplet. This breaking pattern is in principle possible if the quaternion-Kähler space of the hypermultiplet admits (at least) one pair of commuting isometries. For this class of manifolds, explicit metrics exist and we analyse a generic electromagnetic (dyonic) gauging of the isometries. An example of partial breaking in Minkowski spacetime has been found long ago by Ferrara, Girardello and Porrati, using the gauging of two translation isometries on SO(4, 1)/SO(4). We demonstrate that no other example of partial breaking of N = 2 supergravity in Minkowski spacetime exists. We also examine partial-breaking vacua in anti-de Sitter spacetime that are much less constrained and exist generically even for electric gaugings. On SO(4, 1)/SO(4), we construct the partially-broken solution and its global limit which is the Antoniadis–Partouche–Taylor model.
Journal of High Energy Physics, 2016
We study off-shell rigid limits for the kinetic and scalar-potential terms of a single N = 2 hype... more We study off-shell rigid limits for the kinetic and scalar-potential terms of a single N = 2 hypermultiplet. In the kinetic term, these rigid limits establish relations between fourdimensional quaternion-Kähler and hyper-Kähler target spaces with symmetry. The scalar potential is obtained by gauging the graviphoton along an isometry of the quaternion-Kähler space. The rigid limits unveil two distinct cases. A rigid N = 2 theory on Minkowski or on AdS 4 spacetime, depending on whether the isometry is translational or rotational respectively. We apply these results to the quaternion-Kähler space with Heisenberg ⋉ U(1) isometry, which describes the universal hypermultiplet at type-II string one-loop. Contents Introduction 1 1 Hyper-Kähler and quaternionic manifolds with a symmetry 3 2 The kinetic term and the rigid limits 6 3 The scalar potential 11 3.
Nuclear physics B, 2009
Nonlinear supersymmetry is used to compute the general form of the effective D-brane action in ty... more Nonlinear supersymmetry is used to compute the general form of the effective D-brane action in type I string theory compactified to four dimensions in the presence of internal magnetic fields. In particular, the scalar potential receives three contributions: (1) a nonlinear part of the D-auxiliary component, associated to the Dirac-Born-Infeld action; (2) a Fayet-Iliopoulos (FI) D-term with a moduli-dependent coefficient; (3) a D-auxiliary independent (but moduli dependent) piece from the D-brane tension. Minimization of this potential leads to three general classes of vacua with moduli stabilization: (i) supersymmetric vacua allowing in general FI terms to be cancelled by non-trivial vacuum expectation values (VEV's) of charged scalar fields; (ii) anti-de Sitter vacua of broken supersymmetry in the presence of a non-critical dilaton potential that can be tuned at arbitrarily weak string coupling; (iii) if the dilaton is fixed in a supersymmetric way by threeform fluxes and in the absence of charged scalar VEV's, one obtains non supersymmetric vacua with positive vacuum energy.
The European Physical Journal C
Recently, a new type of constant Fayet–Iliopoulos (FI) terms was introduced in $${\mathcal {N}}=1... more Recently, a new type of constant Fayet–Iliopoulos (FI) terms was introduced in $${\mathcal {N}}=1$$ N = 1 supergravity, which do not require the gauging of the R-symmetry. We revisit and generalise these constructions, building a new class of Kähler invariant FI terms parametrised by a function of the gravitino mass as functional of the chiral superfields, which is then used to describe new models of inflation. They are based on a no-scale supergravity model of the inflaton chiral multiplet, supplemented by an abelian vector multiplet with the new FI-term. We show that the inflaton potential is compatible with the CMB observational data, with a vacuum energy at the minimum that can be tuned to a tiny positive value. Finally, the axionic shift symmetry can be gauged by the U(1) which becomes massive. These models offer a mechanism for fixing the gravitino mass in no-scale supergravities, that corresponds to a flat direction of the scalar potential in the absence of the new FI-term; i...
Journal of High Energy Physics
Gravitinos can inherit a non-relativistic dispersion relation while propagating in a background b... more Gravitinos can inherit a non-relativistic dispersion relation while propagating in a background breaking both supersymmetry and Lorentz symmetry spontaneously. This is because the longitudinal mode velocity is controlled by the sound speed in the background. It was pointed out recently by Kolb, Long and McDonough that the production of gravitinos might diverge when this sound speed vanishes. We argue that in the framework of cosmological models with linearly spontaneously broken realised supersymmetry, where the physical fermions are combinations of the vacuum goldstino and the inflatino, the gravitino longitudinal mode has a relativistic dispersion relation and therefore avoids the catastrophic production. We illustrate this in some explicit examples.
The European Physical Journal C
We construct a regular five-dimensional brane-world with localised gravity on a flat 3-brane. The... more We construct a regular five-dimensional brane-world with localised gravity on a flat 3-brane. The matter content in the bulk is parametrised by an analog of a non-linear fluid with equation of state $$p=\gamma \rho ^\lambda $$ p = γ ρ λ between the ‘pressure’ p and the ‘density’ $$\rho $$ ρ dependent on the 5th dimension. For $$\gamma $$ γ negative and $$\lambda >1$$ λ > 1 , the null energy condition is satisfied and the geometry is free of singularities within finite distance from the brane, while the induced four-dimensional Planck mass is finite.
Journal of High Energy Physics
We consider the most general Kaluza-Klein (KK) compactification on S1/ℤ2 of a five dimensional (5... more We consider the most general Kaluza-Klein (KK) compactification on S1/ℤ2 of a five dimensional (5D) graviton-dilaton system, with a non-vanishing dilaton background varying linearly along the fifth dimension. We show that this background produces a Higgs mechanism for the KK vector coming from the 5D metric, which becomes massive by absorbing the string frame radion. The $$ \mathcal{N} $$ N = 2 minimal supersymmetric extension of this model, recently built as the holographic dual of Little String Theory, is then reinvestigated. An analogous mechanism can be considered for the 4D vector coming from the (universal) 5D Kalb-Ramond two-form. Packaging the two massive vectors into a spin-3/2 massive multiplet, it is shown that the massless spectrum arranges into a $$ \mathcal{N} $$ N = 1, D = 4 supersymmetric theory. This projection is compatible with an orbifold which preserves half of the original supersymmetries already preserved by the background. The description of the partial break...
The European Physical Journal C
We study the cosmological properties of a metastable de Sitter vacuum obtained recently in the fr... more We study the cosmological properties of a metastable de Sitter vacuum obtained recently in the framework of type IIB flux compactifications in the presence of three D7-brane stacks, based on perturbative quantum corrections at both world-sheet and string loop level that are dominant at large volume and weak coupling. In the simplest case, the model has one effective parameter controlling the shape of the potential of the inflaton which is identified with the volume modulus. The model provides a phenomenological successful small-field inflation for a value of the parameter that makes the minimum very shallow and near the maximum. The horizon exit is close to the inflection point while most of the required e-folds of the Universe expansion are generated near the minimum, with a prediction for the ratio of tensor-to-scalar primordial fluctuations $$r\simeq 4\times 10^{-4}$$ r ≃ 4 × 10 - 4 . Despite its shallowness, the minimum turns out to be practically stable. We show that it can dec...
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Papers by Ignatios Antoniadis