Large deviations for the local particle densities

We analyze the relations between the large deviation principle of the “local” particle densities of the x− and k−spaces respectively. Here the k−space means the space of momentums (the Fourier transform counterpart of the x− space). This study gives new insights on the results of papers [2], where the authors have found the corresponding large deviation principle of the local particle density in the x− space. In particular, for a very large class of stable Hamiltonians we show that the “local” particle densities (x− and k−spaces) are equal to each other from the point of view of the large deviation principle. In other words, the “local” particle densities in the x− and k−spaces are in this case exponentially equivalent [1]. Applying this result to the specific case of the Perfect Bose Gas, we found an alternative proof to the one done in [2]

Single- and double-drift bunchers as possible injection schemes for the CPS linac

Two bunching schemes are considered in the frame of the CPS Linac, one with a single buncher, the other with a double-drift harmonic buncher. The matching of the beam to the Linac acceptance in six phase-space dimensions is achieved by computer programs in an iterative way: zero current solutions are found first, and then the intensity is progressively raised until 200 mA are trapped into the Linac. (9 refs)

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}

A New Microscopic Theory of Superfluidity at all Temperatures

Following the program suggested in [1], we get a new microscopic theory of superfluidity for all temperatures and densities. In particular, the corresponding phase diagram of this theory exhibits: (i) a thermodynamic behavior corresponding to the Mean-Field Gas for small densities or high temperatures, (ii) the ”Landau-type” excitation spectrum in the presence of non-conventional Bose condensation for high densities or small temperatures, (iii) a coexistence of particles inside and outside the condensate with the formation of “Cooper pairs”, even at zero-temperature (experimentally, an estimate of the fraction of condensate in liquid 4 He at T=0 K is 9 %, see [2, 3]). In contrast to Bogoliubov’s last approach and with the caveat that the full interacting Hamiltonian is truncated, the analysis performed here is rigorous by involving for the first time a complete thermodynamic analysis of a non-trivial continuous gas in the canonical ensemble

Validation of the mindful coping scale

This is an electronic copy of an article that was originally published by Taylor & Francis as follows: Tharaldsen, K.B. and Bru, E. (2011) Validation of the mindful coping scale. Emotional and Behavioural Difficulties , 16(1), pp. 87-103. For the original article; see http://dx.doi.org/10.1080/13632752.2011.545647.The aim of this research is to develop and validate a self-report measure of mindfulness and coping, the mindful coping scale (MCS). Dimensions of mindful coping were theoretically deduced from mindfulness theory and coping theory. The MCS was empirically evaluated by use of factor analyses, reliability testing and nomological network validation. The study’s participants were high school students from two high schools, covering all streams. Further validation was obtained by correlating the MCS-subscales with an appraisal theory-based measure of coping strategies. Results from factor analyses supported the proposed measurement model and Cronbach’s alphas indicated good internal consistency for the four sub-scales. Furthermore, correlations with instrument for measuring coping were mainly in accordance with our expectations. The above supports the validation of our instrument

Critical Analysis of the Bogoliubov Theory of Superfluidity

The microscopic theory of superfluidity [1—3] was proposed by Bogoliubov in 1947 to explain the Landau-type excitation spectrum of He-4. An analysis of the Bogoliubov theory has already been performed in the recent review [4]. Here we add some new critical analyses of this theory. This leads us to consider the superstable Bogoliubov model [5]. It gives rise to an improvement of the previous theory which will be explained with more details in a next paper [6]: coexistence in the superfluid liquid of particles inside and outside the Bose condensate (even at zero temperature), Bose/Bogoliubov statistics, “Cooper pairs” in the Bose condensate, Landau-type excitation spectrum..

A new theory of superfluidity

The understanding of superfluidity represents one of the most challenging problems in modern physics. From the observations of [1-3], in various respects the Bogoliubov theory [4—8] is not appropriate as the model of superfluidity for Helium 4. His outstanding achievement, i.e., the derivation of the Landau-type excitation spectrum [9, 10] from the full interacting Hamiltonian, is based on a series of recipes or approximations, which were shown to be wrong, even from their starting point [11—14]. We therefore present some very promising new results performed in [15]. In particular, we explain a new theory of superfluidity at all temperatures. At this point we then touch one of the most fascinating problems of contemporary mathematical physics the proof of the existence of superfluidity in interacting (non-dilute) systems

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

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