A torsional completion of gravity for Dirac matter fields and its applications to neutrino oscillations

In this paper, we consider the torsional completion of gravitation for an underlying background filled with Dirac fields, applying it to the problem of neutrino oscillations: we discuss the effects of the induced torsional interactions as corrections to the neutrino oscillation mechanism.Comment: 4 page

An LQ problem for the heat equation on the halfline with Dirichlet boundary control and noise

We study a linear quadratic problem for a system governed by the heat equation on a halfline with Dirichlet boundary control and Dirichlet boundary noise. We show that this problem can be reformulated as a stochastic evolution equation in a certain weighted L2 space. An appropriate choice of weight allows us to prove a stronger regularity for the boundary terms appearing in the infinite dimensional state equation. The direct solution of the Riccati equation related to the associated non-stochastic problem is used to find the solution of the problem in feedback form and to write the value function of the problem.Comment: 16 pages. Many misprints have been correcte

An Hilbert space approach for a class of arbitrage free implied volatilities models

We present an Hilbert space formulation for a set of implied volatility models introduced in \cite{BraceGoldys01} in which the authors studied conditions for a family of European call options, varying the maturing time and the strike price $T$ an $K$, to be arbitrage free. The arbitrage free conditions give a system of stochastic PDEs for the evolution of the implied volatility surface ${\hat\sigma}_t(T,K)$. We will focus on the family obtained fixing a strike $K$ and varying $T$. In order to give conditions to prove an existence-and-uniqueness result for the solution of the system it is here expressed in terms of the square root of the forward implied volatility and rewritten in an Hilbert space setting. The existence and the uniqueness for the (arbitrage free) evolution of the forward implied volatility, and then of the the implied volatility, among a class of models, are proved. Specific examples are also given.Comment: 21 page

Spontaneous breaking of conformal invariance in theories of conformally coupled matter and Weyl gravity

We study the theory of Weyl conformal gravity with matter degrees of freedom in a conformally invariant interaction. Specifically, we consider a triplet of scalar fields and SO(3) non-abelian gauge fields, i.e. the Georgi-Glashow model conformally coupled to Weyl gravity. We show that the equations of motion admit solutions spontaneously breaking the conformal symmetry and the gauge symmetry, providing a mechanism for supplying a scale in the theory. The vacuum solution corresponds to anti-de-Sitter space-time, while localized soliton solutions correspond to magnetic monopoles in asymptotically anti-de-Sitter space-time. The resulting effective action gives rise to Einstein gravity and the residual U(1) gauge theory. This mechanism strengthens the reasons for considering conformally invariant matter-gravity theory, which has shown promising indications concerning the problem of missing matter in galactic rotation curves.Comment: 20 pages, 1 figure, revised and added reference

Entanglement of Dirac fields in an expanding spacetime

We study the entanglement generated between Dirac modes in a 2-dimensional conformally flat Robertson-Walker universe. We find radical qualitative differences between the bosonic and fermionic entanglement generated by the expansion. The particular way in which fermionic fields get entangled encodes more information about the underlying space-time than the bosonic case, thereby allowing us to reconstruct the parameters of the history of the expansion. This highlights the importance of bosonic/fermionic statistics to account for relativistic effects on the entanglement of quantum fields.Comment: revtex4, 7 figures, I.F. previously published as Fuentes-Guridi and Fuentes-Schuller. Journal reference update

Non-local density correlations as signal of Hawking radiation in BEC acoustic black holes

We have used the analogy between gravitational systems and non-homogeneous fluid flows to calculate the density-density correlation function of an atomic Bose-Einstein condensate in the presence of an acoustic black hole. The emission of correlated pairs of phonons by Hawking-like process results into a peculiar long-range density correlation. Quantitative estimations of the effect are provided for realistic experimental configurations.Comment: Strongly revised version. 5 pages, 3 eps figure

Two-dimensional black holes in accelerated frames: quantum aspects

By considering charged black hole solutions of a one parameter family of two dimensional dilaton gravity theories, one finds the existence of quantum mechanically stable gravitational kinks with a simple mass to charge relation. Unlike their Einsteinian counterpart (i.e. extreme Reissner-Nordstr\"om), these have nonvanishing horizon surface gravity.Comment: 18 pages, harvmac, 2 figure

Understanding the stressful implications of remote e-working: Evidence from Europe

This paper investigate the importance of different modes of spatial flexibility as well as of the distinction between autonomy and discretion to find plausible explanations of the so-called autonomy paradox, that is the more the job autonomy that remote e-workers have the greater the effort they put into their work with adverse effects on work-related stress. Using multiple regressions, we test the hypotheses regarding the direct influence of autonomy, discretion and work intensification as well as their interaction effects on occupational stress in two subsamples of 1.380 home-based e-workers and 2.574 mobile ones drawn from the 2015 European Working Conditions Survey. The main findings are as follows. Home-based eworkers perceive that autonomy (namely over work goals) directly decreases occupational stress and buffers work intensification (i.e. autonomy over work goals and in the organizational choices of their department/company). In the context of remote e-work, discretion is more likely to boost the stressful impact of work intensification when work is mobile, demanding to managing complex relationships with a high number of different interest groups and thus more uncertain. At the same time, we do not find that autonomy increases work intensification, neither among mobile e-workers, nor among home-based eworkers (for whom it buffers the adverse impact of work intensification). In summary, this study does not confirm the existence of an autonomy paradox associated with remote e-work. Contrarily, it suggests that such a paradox is more likely to surface when research is based on the JD-C and JD-R frameworks or other approaches that like the former ambiguously define autonomy in terms of what should be more properly conceptualized as discretion