1,105 research outputs found
Matrix Model Maps and Reconstruction of AdS SUGRA Interactions
We consider the question of reconstructing (cubic) SUGRA interactions in
AdS/CFT. The method we introduce is based on the matrix model maps (MMP) which
were previously successfully employed at the linearized level. The strategy is
to start with the map for 1/2 BPS configurations which is exactly known (to all
orders) in the hamiltonian framework. We then use the extension of the matrix
model map with the corresponding Ward identities to completely specify the
interaction. A central point in this construction is the non-vanishing of
off-shell interactions (even for highest-weight states).Comment: 28 page
Inverted Oscillator
The inverted harmonic oscillator problem is investigated quantum
mechanically. The exact wave function for the confined inverted oscillator is
obtained and it is shown that the associated energy eigenvalues are discrete
and it is given as a linear function of the quantum number .Comment: 4 page
Supersymmetric Wilson loops via integral forms
We study supersymmetric Wilson loops from a geometrical perspective. To this end, we propose a new formulation of these operators in terms of an integral form associated to the immersion of the loop into a supermanifold. This approach provides a unifying description of Wilson loops preserving different sets of supercharges, and clarifies the flow between them. Moreover, it allows to exploit the powerful techniques of super- differential calculus for investigating their symmetries. As remarkable examples, we discuss supersymmetry and kappa-symmetry invariance
Higher Derivative Corrections to R-charged Black Holes: Boundary Counterterms and the Mass-Charge Relation
We carry out the holographic renormalization of Einstein-Maxwell theory with
curvature-squared corrections. In particular, we demonstrate how to construct
the generalized Gibbons-Hawking surface term needed to ensure a perturbatively
well-defined variational principle. This treatment ensures the absence of ghost
degrees of freedom at the linearized perturbative order in the
higher-derivative corrections. We use the holographically renormalized action
to study the thermodynamics of R-charged black holes with higher derivatives
and to investigate their mass to charge ratio in the extremal limit. In five
dimensions, there seems to be a connection between the sign of the higher
derivative couplings required to satisfy the weak gravity conjecture and that
violating the shear viscosity to entropy bound. This is in turn related to
possible constraints on the central charges of the dual CFT, in particular to
the sign of c-a.Comment: 30 pages. v2: references added, some equations simplifie
Higher Derivative Extension of 6D Chiral Gauged Supergravity
Six-dimensional (1,0) supersymmetric gauged Einstein-Maxwell supergravity is
extended by the inclusion of a supersymmetric Riemann tensor squared invariant.
Both the original model as well as the Riemann tensor squared invariant are
formulated off-shell and consequently the total action is off-shell invariant
without modification of the supersymmetry transformation rules. In this
formulation, superconformal techniques, in which the dilaton Weyl multiplet
plays a crucial role, are used. It is found that the gauging of the U(1)
R-symmetry in the presence of the higher-order derivative terms does not modify
the positive exponential in the dilaton potential. Moreover, the supersymmetric
Minkowski(4) x S^2 compactification of the original model, without the
higher-order derivatives, is remarkably left intact. It is shown that the model
also admits non-supersymmetric vacuum solutions that are direct product spaces
involving de Sitter spacetimes and negative curvature internal spaces.Comment: 32 pages; typos corrected, footnote in conclusions section adde
On the Temperature Dependence of the Shear Viscosity and Holography
We examine the structure of the shear viscosity to entropy density ratio
eta/s in holographic theories of gravity coupled to a scalar field, in the
presence of higher derivative corrections. Thanks to a non-trivial scalar field
profile, eta/s in this setup generically runs as a function of temperature. In
particular, its temperature behavior is dictated by the shape of the scalar
potential and of the scalar couplings to the higher derivative terms. We
consider a number of dilatonic setups, but focus mostly on phenomenological
models that are QCD-like. We determine the geometric conditions needed to
identify local and global minima for eta/s as a function of temperature, which
translate to restrictions on the signs and ranges of the higher derivative
couplings. Finally, such restrictions lead to an holographic argument for the
existence of a global minimum for eta/s in these models, at or above the
deconfinement transition.Comment: references adde
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