International School for Advanced Studies

About: International School for Advanced Studies is a education organization based out in Trieste, Friuli-Venezia Giulia, Italy. It is known for research contribution in the topics: Galaxy & Dark matter. The organization has 3751 authors who have published 13433 publications receiving 588454 citations. The organization is also known as: SISSA & Scuola Internazionale Superiore di Studi Avanzati.

The windows for kinetically mixed Z′-mediated dark matter and the galactic center gamma ray excess

Abstract: One of the simplest hidden sectors with signatures in the visible sector is fermionic dark mattercoupled to a Z 0 gauge boson that has purely kinetic mixing with the standard model hypercharge. We consider the combined constraints from relic density, direct detection and collider experiments on such models in which the dark matter is either a Dirac or a Majorana fermion. We point out sensitivity to details of the UV completion for the Majorana model. For kinetic mixing parameter � � 0:01, only relic density and direct detection are relevant, while for larger �, electroweak precision, LHC dilepton, and missing energy constraints become important. We identify regions of the parameter space of m�, mZ 0, dark gauge coupling andthat are most promising for discovery through these experimental probes. We study the compatibility of the models with the galactic center gamma ray excess, �nding agreement at the 2-3� level for the Dirac model.

Lagrangians for generalized Argyres-Douglas theories

Abstract: We continue the study of Lagrangian descriptions of $$ \mathcal{N}=2 $$ Argyres-Douglas theories. We use our recent interpretation in terms of sequential confinement to guess the Lagrangians of all the Argyres-Douglas models with Abelian three dimensional mirror. We find classes of four dimensional $$ \mathcal{N}=1 $$ quivers that flow in the infrared to generalized Argyres-Douglas theories, such as the (A k , A kN +N −1) models. We study in detail how the $$ \mathcal{N}=1 $$ chiral rings map to the Coulomb and Higgs Branches of the $$ \mathcal{N}=2 $$ CFT’s. The three dimensional mirror RG flows are shown to land on the $$ \mathcal{N}=4 $$ complete graph quivers. We also compactify to three dimensions the gauge theory dual to (A 1, D 4), and find the expected Abelianization duality with $$ \mathcal{N}=4 $$ SQED with 3 flavors.

Topology of the fittest transportation network.

Abstract: The presence or absence of loops in the emergent transportation networks, that are characterized by a minimum overall cost, is shown to depend on the convexity of the cost function for the local transportation of material. Our results are directly applicable to a variety of situations across disciplines.

Vainshtein Screening in Scalar-Tensor Theories before and after GW170817: Constraints on Theories beyond Horndeski

Abstract: Screening mechanisms are essential features of dark energy models mediating a fifth force on large scales. We study the regime of strong scalar field nonlinearities, known as Vainshtein screening, in the most general scalar-tensor theories propagating a single scalar degree of freedom. We first develop an effective approach to parametrize cosmological perturbations beyond linear order for these theories. In the quasistatic limit, the fully nonlinear effective Lagrangian contains six independent terms, one of which starts at cubic order in perturbations. We compute the two gravitational potentials around a spherical body. Outside and near the body, screening reproduces standard gravity, with a modified gravitational coupling. Inside the body, the two potentials are different and depend on the density profile, signalling the breaking of the Vainshtein screening. We provide the most general expressions for these modifications, revising and extending previous results. We apply our findings to show that the combination of the GW170817 event, the Hulse-Taylor pulsar and stellar structure physics, constrain the parameters of these general theories at the level of ${10}^{\ensuremath{-}1}$, and of Gleyzes-Langlois-Piazza-Vernizzi theories at the level of ${10}^{\ensuremath{-}2}$.