1,720,977 research outputs found
TBA type equations and tropical curves
No full textThe Joyce integrable system and the corresponding Bridgeland-Toledano-Laredo connections are fundamental objects associated with suitable abelian categories or, more generally, with a class of continuous families of stability data. We offer an overview of some of our work, mostly joint with M. Garcia Fernandez, focusing on equations of TBA type as a useful tool in the analysis of these objects and their deformations, and as a means to establish a connection with tropical geometry
Solutions to Donaldson's Hyperkähler Reduction on a Curve
Full text linkWe study an infinite-dimensional hyperkähler reduction introduced by Donaldson and associated with the constant scalar curvature equation on a Riemann surface. It is known that the corresponding moment map equations admit special solutions constructed from holomorphic quadratic differentials. Here we obtain a more general existence result and so a larger hyperkähler moduli space
Regesto dei documenti
No full textNel contributo sono registrati in ordine cronologico tutti i documenti relativi all'attività del pittore Bernardino Luini e dei suoi figli Aurelio e Giovanni Pietro. Sono prese in considerazione anche tutti gli atti relativi alla biografia del cognato di Bernardino, il pittore Battista Balduini da Lecc
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Francesco De Tatti nei documenti
No full textNel saggio è delineato un profilo biografico ed è ripercorsa la carriera del pittore originario di Varese Francesco Tatti sulla scorta anche della documentazione rinvenuta sull'artista
Documenti
No full textNel contributo sono editati in ordine cronologico tutti i documenti inerenti la carriera artistica del pittore varesino Francesco Tatti. Secondo modalità già sperimentate per simili raccolte documentarie, di ciascun documento (numerato progressivamente) innanzitutto sono forniti: data cronica, data topica, un breve regesto, la segnatura archivistica e l'eventuale bibliografia relativa. Seguono poi la trascrizioni dei singoli atti, dalle quali sono stati omessi formulari superflu
Stability data, irregular connections and tropical curves
No full textWe study a class of meromorphic connections ∇ (Z) on P1, parametrised by the central charge Z of a stability condition, with values in a Lie algebra of formal vector fields on a torus. Their definition is motivated by the work of Gaiotto, Moore and Neitzke on wall-crossing and three-dimensional field theories. Our main results concern two limits of the families ∇ (Z) as we rescale the central charge Z↦ RZ. In the R→ 0 “conformal limit” we recover a version of the connections introduced by Bridgeland and Toledano Laredo (and so the Joyce holomorphic generating functions for enumerative invariants), although with a different construction yielding new explicit formulae. In the R→ ∞ “large complex structure” limit the connections ∇ (Z) make contact with the Gross–Pandharipande–Siebert approach to wall-crossing based on tropical geometry. Their flat sections display tropical behaviour, and also encode certain tropical/relative Gromov–Witten invariants
Frobenius type and CV-structures for Donaldson-Thomas theory and a convergence property
Full text linkWe rephrase some well-known results in Donaldson–Thomas theory in terms of (formal families of) Frobenius type and CV-structures on a vector bundle in the sense of Hertling. We study these structures in an abstract setting, and prove a convergence result which is relevant to the case of triangulated categories. An application to physical field theory is also briefly discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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