Large Deviations in the Superstable Weakly Imperfect Bose Gas

The superstable Weakly Imperfect Bose Gas {(WIBG)} was originally derived to solve the inconsistency of the Bogoliubov theory of superfluidity. Its grand-canonical thermodynamics was recently solved but not at {point of} the {(first order)} phase transition. This paper proposes to close this gap by using the large deviations formalism and in particular the analysis of the Kac distribution function. It turns out that, as a function of the chemical potential, the discontinuity of the Bose condensate density at the phase transition {point} disappears as a function of the particle density. Indeed, the Bose condensate continuously starts at the first critical particle density and progressively grows but the free-energy per particle stays constant until the second critical density is reached. At higher particle densities, the Bose condensate density as well as the free-energy per particle both increase {monotonously}

Application to the SPIRAL project at GANIL of a new kind of large acceptance mass separator

International audienc

The difference of boundary effects between Bose and Fermi systems

In this paper, we show that there exists an essential difference of boundary effects between Bose and Fermi systems both for Dirichlet and Neumann boundary conditions: at low temperatures and high densities the influence of the boundary on the Bose system depends on the temperature but is independent of the density, but for the Fermi case the influence of the boundary is independent of the temperature but depends on the density, after omitting the negligible high-order corrections. We also show that at high temperatures and low densities the difference of the influence of the boundary between Bose and Fermi systems appears in the next-to-leading order boundary contribution, and the leading boundary contribution is independent of the density. Moreover, for calculating the boundary effects at high temperatures and low densities, since the existence of the boundary modification causes the standard virial expansion to be invalid, we introduce a modified virial expansion.Comment: 8 page

Exercise: a path to wellness during adjuvant chemotherapy for breast cancer?

Background: Breast cancer treatment can represent a threat to a patient’s wellness. The role of exercise in perceived wellness in women with breast cancer merits further study. Objective: The objective of this study was to describe how exercise is perceived by women to influence their physical and psychosocial wellness at the time they were receiving chemotherapy. Methods: Five focus group interviews with a total of 27 women with early-stage breast cancer were conducted. Prior to the focus groups, the women had participated in an exercise intervention during chemotherapy treatment. Results: Three themes emerged from the analysis: exercise shapes feelings of psychological wellness; exercise stimulates feelings of physical wellness; and exercise influences social wellness. The women reported feeling stronger in a psychological sense after exercising, that the strength exercise improved their upper-limb functioning, and that engaging in exercise triggered social support and interactions. Conclusions: Exercise during breast cancer treatment is perceived to enhance the patients’ wellness on several dimensions and in particular psychological wellness. Exercise might support the patients’ efforts to restore their sense of wellness and enhance their level of daily life functioning. Implications for Practice: Cancer nurses should promote exercise as a wellness-fostering intervention during chemotherapy treatment. Focusing on how exercise can contribute to feelings of wellness may help women with breast cancer choose exercise as a health-promoting activity that contributes to their recovery

Factors perceived to influence exercise adherence in women with breast cancer participating in an exercise programme during adjuvant chemotherapy: a focus group study

Aims and objectives. To explore factors influencing exercise adherence among women with breast cancer while following an exercise programme. Background. Earlier research shows that women with breast cancer decrease physical activity following the cancer diagnosis and that adhering to exercise interventions can be a challenge. Research is needed to identify motivational factors and barriers for exercise adherence among women during treatment for breast cancer. Design. This was a qualitative study to explore patient’s perceptions of the challenges to exercise adherence during a randomised, controlled trial. Methods. Twenty-seven women with early-stage breast cancer were purposively sampled for focus group interviews during 2011–2012 from their participation in the exercise intervention group during 2010–2012. Five focus groups were performed, and data analysis was completed using the systematic text condensation method. Results. During the focus group study, five main themes were identified, which described factors participants perceived to influence their adherence to exercise during chemotherapy: ‘side effects of breast cancer treatment as a barrier to exercise’, ‘restoring and maintaining normality in daily life motivates exercise’, ‘other valued activities compete with exercise’, ‘constructive support enhances exercise’ and ‘positive beliefs about efficacy and outcomes motivate exercise’. Conclusion. Adherence to exercise in women with breast cancer is challenged by internal and external conditions and may be improved by attention to the impact of treatment side effects and by supporting patient self-efficacy towards changing health behaviour. Relevance to clinical practice. Nurses should be aware that exercise adherence could be a challenge among women with breast cancer. They should help identify obstacles to exercise for women and ways to overcome them, as well as support them in their beliefs that they are capable of changing their health behaviou

Trajectory Tracking Control of a Timed Event Graph with Specifications Defined by a P-time Event Graph

The aim of this paper is a trajectory tracking control of Timed Event Graphs with specifications defined by a P-time Event Graph. Two problems are solved on a fixed horizon knowing the current state: The optimal control for favorable past evolution; The prediction of the earliest future evolution of the process. These two parts make up an on-line control which is used on a sliding horizon. Completely defined in (max, +) algebra, the proposed approach is a Model Predictive Control using the componentwise order relation

Quantum Fluctuations and Large Deviation Principle for Microscopic Currents of Free Fermions in Disordered Media

We contribute an extension of large-deviation results obtained in [N.J.B. Aza, J.-B. Bru, W. de Siqueira Pedra, A. Ratsimanetrimanana, J. Math. Pures Appl. 125 (2019) 209] on conductivity theory at atomic scale of free lattice fermions in disordered media. Disorder is modeled by (i) a random external potential, like in the celebrated Anderson model, and (ii) a nearest-neighbor hopping term with random complex-valued amplitudes. In accordance with experimental observations, via the large deviation formalism, our previous paper showed in this case that quantum uncertainty of microscopic electric current densities around their (classical) macroscopic value is suppressed, exponentially fast with respect to the volume of the region of the lattice where an external electric field is applied. Here, the quantum fluctuations of linear response currents are shown to exist in the thermodynamic limit and we mathematically prove that they are related to the rate function of the large deviation principle associated with current densities. We also demonstrate that, in general, they do not vanish (in the thermodynamic limit) and the quantum uncertainty around the macroscopic current density disappears exponentially fast with an exponential rate proportional to the squared deviation of the current from its macroscopic value and the inverse current fluctuation, with respect to growing space (volume) scales.FAPESP (2017/22340-9); CNPq (309723/2020-5); by the Basque Government through the grant IT641-13; MTM2017-82160-C2-2-

Microscopic Conductivity of Lattice Fermions at Equilibrium - Part I: Non-Interacting Particles

We consider free lattice fermions subjected to a static bounded potential and a time- and space-dependent electric field. For any bounded convex region $\mathcal{R}\subset \mathbb{R}^{d}$ ($d\geq 1$) of space, electric fields $\mathcal{E}$ within $\mathcal{R}$ drive currents. At leading order, uniformly with respect to the volume $\left| \mathcal{R}\right|$ of $\mathcal{R}$ and the particular choice of the static potential, the dependency on $\mathcal{E}$ of the current is linear and described by a conductivity distribution. Because of the positivity of the heat production, the real part of its Fourier transform is a positive measure, named here (microscopic) conductivity measure of $\mathcal{R}$, in accordance with Ohm's law in Fourier space. This finite measure is the Fourier transform of a time-correlation function of current fluctuations, i.e., the conductivity distribution satisfies Green-Kubo relations. We additionally show that this measure can also be seen as the boundary value of the Laplace-Fourier transform of a so-called quantum current viscosity. The real and imaginary parts of conductivity distributions satisfy Kramers-Kronig relations. At leading order, uniformly with respect to parameters, the heat production is the classical work performed by electric fields on the system in presence of currents. The conductivity measure is uniformly bounded with respect to parameters of the system and it is never the trivial measure $0\,\mathrm{d}\nu$. Therefore, electric fields generally produce heat in such systems. In fact, the conductivity measure defines a quadratic form in the space of Schwartz functions, the Legendre-Fenchel transform of which describes the resistivity of the system. This leads to Joule's law, i.e., the heat produced by currents is proportional to the resistivity and the square of currents

A parallel algorithm for the partial single-input pole assignment problem

AbstractFor a linear control system, we introduce a parallel algorithm to assign a desired subset of eigenvalues to a single-input linear invariant dynamic system. We obtain a sequential algorithm as a particular case. The proposed algorithms are conceptually simple and are based on the computation of left eigenvectors of the state matrix. In addition, the parallel algorithm parallelizes easily as the numerical examples show