Representation of non-semibounded quadratic forms and orthogonal additivity

In this article we give a representation theorem for non-semibounded Hermitean quadratic forms in terms of a (non-semibounded) self-adjoint operator. The main assumptions are closability of the Hermitean quadratic form, the direct integral structure of the underlying Hilbert space and orthogonal additivity. We apply this result to several examples, including the position operator in quantum mechanics and quadratic forms invariant under a unitary representation of a separable locally compact group. The case of invariance under a compact group is also discussed in detail

Notions of Infinity in Quantum Physics

In this article we will review some notions of infiniteness that appear in Hilbert space operators and operator algebras. These include proper infiniteness, Murray von Neumann's classification into type I and type III factors and the class of F{/o} lner C*-algebras that capture some aspects of amenability. We will also mention how these notions reappear in the description of certain mathematical aspects of quantum mechanics, quantum field theory and the theory of superselection sectors. We also show that the algebra of the canonical anti-commutation relations (CAR-algebra) is in the class of F{/o} lner C*-algebras.Comment: 11 page

Introducing migratory flows in life table construction

The purpose of life tables is to describe the mortality behaviour of particular groups. The construction of general life tables is based on death statistics and census figures of resident populations under the hypothesis of closed demographic system. Among other assumptions, this hypothesis implicitly assumes that entries (immigrants) and exits (emigrants) of the population are usually not significant (being almost of the same magnitude for each age compensating each other). This paper theoretically extends the classical solution to open demographic systems and studies the impact of this hypothesis in constructing a life table. In particular, using the data of residential variations made available to the public by the Spanish National Statistical Office (INE, Instituto Nacional de Estadística) to approximate migratory flows, we introduce in the process of constructing a life table these flows and compare, before and after graduation, the crude mortality rates and the adjusted death probabilities obtained when migratory flows are, and are not, taken into account

En los límites de la representación

En esta tesis se estudia y define un componente estético-expresivo que aparece en una determinada producción artística contemporánea realizada con métodos constructivos y formas depuradas, que poseen un tipo de significación fronteriza situable entre la presencia y la representación, conceptos antitéticos que conviven dinámicamente en este tipo de obras determinando un modo peculiar de funcionamiento que incide decisivamente en el sentido que configuran y el valor que adquieren en ella se establece el discurso artístico general que hace posible la aparición de esta producción y se analiza y determina el conjunto de poéticas que inciden en su constitución. Finalmente se estudia la producción resultante y se define el componente estético y expresivo que sustenta sus modos de acción

Twisted duality of the CAR-Algebra

We give a complete proof of the twisted duality property M(q)'= Z M(q^\perp) Z* of the (self-dual) CAR-Algebra in any Fock representation. The proof is based on the natural Halmos decomposition of the (reference) Hilbert space when two suitable closed subspaces have been distinguished. We use modular theory and techniques developed by Kato concerning pairs of projections in some essential steps of the proof. As a byproduct of the proof we obtain an explicit and simple formula for the graph of the modular operator. This formula can be also applied to fermionic free nets, hence giving a formula of the modular operator for any double cone.Comment: 32 pages, Latex2e, to appear in Journal of Mathematical Physic

Emotionally-driven behaviours among undergraduate women: A preliminary study

here is considerable evidence that a number of apparently impulsive or addictive behaviours (e.g., self - harm, alcohol or substance misuse) can be triggered by negatively valenced affective states, and that the behaviours serve the f unction of blocking awareness of intolerable emotions. However, the evidence base for this pattern of emotionally - driven blocking behaviours is relatively patchy, because there has been little systematic investigation of the emotions that trigger different blocking behaviours. In this preliminary study of emotionally - driven blocking behaviours, 53 non - clinical women completed a self - report measure of the link between specific affective states (anger, anxiety, boredom, depression, loneliness) and different b locking behaviours (smoking; aggression; drinking alcohol; overeating; compulsive spending; stealing; self - harm; ‘risky’ sexual behaviour). The results indicate a relatively specific pattern of association between different emotions and blocking behaviours . In addition, that linkage was stronger when the individual had a higher level of behavioural impulsivity, particularly where the emotion was loneliness or anger. These findings suggest that individuals who display such behaviours might benefit from skill s training for adaptive affect regulation, although further research is needed to determine the generalizability of these results to broader clinical and non - clinical populations

On the deformation quantization of affine algebraic varieties

We compute an explicit algebraic deformation quantization for an affine Poisson variety described by an ideal in a polynomial ring, and inheriting its Poisson structure from the ambient space

Systemic sclerosis and pregnancy outcomes. A retrospective study from a single center

Background: Pregnancy in systemic sclerosis (SSc) patients is no more an infrequent event as it used to be, but literature data on pregnancy outcomes in women with SSc are scarce. The rate of preterm deliveries and intrauterine growth restriction (IUGR) seems to be increased, while the risk of miscarriages is controversial. Moreover, no study compared pregnancy outcomes in SSc with antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE). We performed a retrospective study to compare the pregnancy and disease outcomes of women with SSc with a cohort of age-matched women with systemic lupus erythematosus (SLE), antiphospholipid syndrome (APS), and healthy controls (HC). Methods: A total of 154 pregnancies from SSc, SLE, APS patients, and HC were prospectively followed at the High-Risk Pregnancy Unit of our center from 2008 to 2019. The primary outcome was a composite endpoint of miscarriages, fetal deaths, intrauterine growth restriction (IUGR), preeclampsia, neonatal deaths, preterm birth, and small-for-gestational-age (SGA) newborns. Single adverse pregnancy outcomes (APO) represented secondary endpoints. SSc activity variations in relation to pregnancy were assessed. Results: The risk of APO was significantly higher in SSc patients compared to HC (60.6% vs 10.0%; OR = 14.42; 95% CI 3.70-56.18, p = 0.001) and SLE patients (60.6% vs 37.5%; OR = 3.56; 95% CI 1.29-9.83, p = 0.014). Compared to HC, women with SSc had an increased frequency of first trimester miscarriage (15% vs 0 %; p = 0.016), preeclampsia (12% vs 0%, p = 0.038), and SGA newborns (21.2% vs 0%; p = 0.003). Preterm deliveries were more frequent in SSc pregnancies in comparison with HC (24.2% vs 5%; OR = 6.08; 95% CI 1.19-31.02, p = 0.036) and SLE patients (24.2% vs 7.5%, OR = 5.68; 95% CI 1.1-29.38, p = 0.038). Disease remained stable in all SSc patients during pregnancy and up to 1 year after delivery. Conclusions: We found an increased risk of APO in our SSc cohort in comparison with HC (with higher rates of miscarriages, preeclampsia, SGA newborns, and preterm deliveries) and SLE patients (presenting a higher rate of preterm deliveries). High-risk multidisciplinary management of SSc pregnant women is highly recommended

N=2 Super-Higgs, N=1 Poincare' Vacua and Quaternionic Geometry

In the context of N=2 supergravity we explain the occurrence of partial super-Higgs with vanishing vacuum energy and moduli stabilization in a model suggested by superstring compactifications on type IIB orientifolds with 3-form fluxes. The gauging of axion symmetries of the quaternionic manifold, together with the use of degenerate symplectic sections for special geometry, are the essential ingredients of the construction.Comment: 18 page

Advances in the subseasonal prediction of extreme events: relevant case studies across the globe

Extreme weather events have devastating impacts on human health, economic activities, ecosystems, and infrastructure. It is therefore crucial to anticipate extremes and their impacts to allow for preparedness and emergency measures. There is indeed potential for probabilistic subseasonal prediction on time scales of several weeks for many extreme events. Here we provide an overview of subseasonal predictability for case studies of some of the most prominent extreme events across the globe using the ECMWF S2S prediction system: heatwaves, cold spells, heavy precipitation events, and tropical and extratropical cyclones. The considered heatwaves exhibit predictability on time scales of 3–4 weeks, while this time scale is 2–3 weeks for cold spells. Precipitation extremes are the least predictable among the considered case studies. ­Tropical cyclones, on the other hand, can exhibit probabilistic predictability on time scales of up to 3 weeks, which in the presented cases was aided by remote precursors such as the Madden–Julian oscillation. For extratropical cyclones, lead times are found to be shorter. These case studies clearly illustrate the potential for event-dependent advance warnings for a wide range of extreme events. The subseasonal predictability of extreme events demonstrated here allows for an extension of warning horizons, provides advance information to impact modelers, and informs communities and stakeholders affected by the impacts of extreme weather events.Peer Reviewed"Article signat per 40 autors/es: Daniela I. V. Domeisen, Christopher J. White, Hilla Afargan-Gerstman, Ángel G. Muñoz, Matthew A. Janiga, Frédéric Vitart, C. Ole Wulff, Salomé Antoine, Constantin Ardilouze, Lauriane Batté, Hannah C. Bloomfield, David J. Brayshaw, Suzana J. Camargo, Andrew Charlton-Pérez, Dan Collins, Tim Cowan, Maria del Mar Chaves, Laura Ferranti, Rosario Gómez, Paula L. M. González, Carmen González Romero, Johnna M. Infanti, Stelios Karozis, Hera Kim, Erik W. Kolstad, Emerson LaJoie, Llorenç Lledó, Linus Magnusson, Piero Malguzzi, Andrea Manrique-Suñén, Daniele Mastrangelo, Stefano Materia, Hanoi Medina, Lluís Palma, Luis E. Pineda, Athanasios Sfetsos, Seok-Woo Son, Albert Soret, Sarah Strazzo, and Di Tian"Postprint (published version