664 research outputs found
Supersymmetric Field Theories and Isomonodromic Deformations
Full text linkThe topic of this thesis is the recently discovered correspondence between supersymmetric gauge theories, two-dimensional conformal field theories and isomonodromic deformation problems. Its original results are organized in two parts: the first one, based on the papers [1], [2], as well as on some further unpublished results, provides the extension of the correspondence between four-dimensional class S theories and isomonodromic deformation problems to Riemann Surfaces of genus greater than zero. The second part, based on the results of [3], is instead devoted to the study of five-dimensional superconformal field theories, and their relation with q-deformed isomonodromic problems
RETTIFICATORE PER UN SENSORE DI RADIAZIONI IN BANDA THZ, IN PARTICOLARE PER FORMAZIONE DI IMMAGINI, E SISTEMA DI RACCOLTA DI CARICA COMPRENDENTE DETTO RETTIFICATORE
No full textMonodromy dependence and symplectic geometry of isomonodromic tau functions on the torus
Full text linkWe compute the monodromy dependence of the isomonodromic tau function on a
torus with Fuchsian singularities and residue matrices by using its
explicit Fredholm determinant representation. We show that the exterior
logarithmic derivative of the tau function defines a closed one-form on the
space of monodromies and times, and identify it with the generating function of
the monodromy symplectomorphism. As an illustrative example, we discuss the
simplest case of the one-punctured torus in detail. Finally, we show that
previous results obtained in the genus zero case can be recovered in a
straightforward manner using the techniques presented here.Comment: 24 pages, 3 figure
Isomonodromic Tau Functions on a Torus as Fredholm Determinants, and Charged Partitions
Full text linkWe prove that the isomonodromic tau function on a torus with Fuchsian singularities and generic monodromies in GL(N, C) can be written in terms of a Fred holm determinant of Plemelj operators. We further show that the minor expansion of this Fredholm determinant is described by a series labeled by charged partitions. As an example, we show that in the case of SL(2, C) this combinatorial expression takes the form of a dual Nekrasov-Okounkov partition function, or equivalently of a free fermion conformal block on the torus. Based on these results we also propose a definition of the tau function of the Riemann-Hilbert problem on a torus with generic jump on the A-cycle
Multimetric supergravities
Full text linkMaking use of integral forms and superfield techniques we propose supersymmetric extensions of the multimetric gravity Lagrangians in dimensions one, two, three and four. The supersymmetric interaction potential covariantly deforms the bosonic one, producing in particular suitable super-symmetric polynomials generated by the Berezinian. As an additional application of our formalism we construct supersymmetric multi-Maxwell theories in dimensions three and four
N=2*Gauge Theory, Free Fermions on the Torus and Painleve VI
No full textIn this paper we study the extension of Painlevé/gauge theory correspondence to circular quivers by focusing on the special case of SU(2) N= 2 ∗ theory. We show that the Nekrasov–Okounkov partition function of this gauge theory provides an explicit combinatorial expression and a Fredholm determinant formula for the tau-function describing isomonodromic deformations of SL2 flat connections on the one-punctured torus. This is achieved by reformulating the Riemann–Hilbert problem associated to the latter in terms of chiral conformal blocks of a free-fermionic algebra. This viewpoint provides the exact solution of the renormalization group flow of the SU(2) N= 2 ∗ theory on self-dual Ω -background and, in the Seiberg–Witten limit, an elegant relation between the IR and UV gauge couplings. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature
Considerazioni sparse sui tagli dipinti del volumi custoditi all'Archivio Storia del Monte di pietà di Bologna
No full textL'articolo descrive ed analizza le raffigurazioni presenti sul taglio dei libri conservati all'Archivio Storico del Monte di Pietà di Bologna, quasi tutti registri dell'istituzione. Pur di non eccelsa rilevanza stilistica, il corpus, molto coeso, è di grande interesse dal punto di vista tecnico e iconografico
Numerical insights on ionic microgels. Structure and swelling behaviour
Full text linkRecent progress has been made in the numerical modelling of neutral microgel particles with a realistic, disordered structure. In this work we extend this approach to the case of co-polymerised microgels where a thermoresponsive polymer is mixed with acidic groups. We compare the cases where counterions directly interact with microgel charges or are modelled implicitly through a Debye–Hückel description. We do so by performing extensive numerical simulations of single microgels across the volume phase transition (VPT) varying the temperature and the fraction of charged monomers. We find that the presence of charges considerably alters the microgel structure, quantified by the monomer density profiles and by the form factors of the microgels, particularly close to the VPT. We observe significant deviations between the implicit and explicit models, with the latter comparing more favourably to available experiments. In particular, we observe a shift of the VPT temperature to larger values as the amount of charged monomers increases. We also find that below the VPT the microgel–counterion complex is almost neutral, while it develops a net charge above the VPT. Interestingly, under these conditions the collapsed microgel still retains a large amount of counterions inside its structure. Since these interesting features cannot be captured by the implicit model, our results show that it is crucial to explicitly include the counterions in order to realistically model ionic thermoresponsive microgels
Terahertz rectifyier for integrated image detector
Full text linkWe present a new CMOS compatible direct conversion terahertz detector operating at room temperature. The rectenna consists in a truncated conical helix extruded from a planar spiral and connected to a nanometric metallic whisker at one of its edges. The whisker reaches the semiconductor substrate that constitutes the antenna ground plane. The rectifying device can be obtained introducing some simple modifications of the charge storage well in conventional CMOS APS devices, making the proposed solution easy to integrate with existing imaging systems. No need of scaling toward very scaled and costly technological node is required, since the CMOS only provides the necessary integrated readout electronics. On-wafer measurements of RF characteristics of the designed rectifying junction are reported and discussed
Il cippo confinario del Monte Ramaceto. Una testimonianza unica nel Tigullio d'età Romana. Video documentario a cura di F. Benente e A. Bertero
No full textVideo documentario (durata 10 minuti) con interviste e con documentazione del ritrovamento del cippo confinario romano del Monte Ramaceto (GE). Il video è inserito nell'allestimento permanente del Museo Archeologico e della Città di Sestri Levante ed è disponibile on line, nella pagina del muse
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