Jean-Baptiste Say et la révolution industrielle… ou les certitudes d'un entrepreneur du secteur textile

International audienceFrom three texts by Jean-Baptiste Say (Olbie ... 1800, Full Course…1819 and a Letter to Malthus in 1820 processing machinery) and a historical approach to technical changes of this period, we will make three observations : 1. Say-entrepreneur is at the heart of the industrial revolution but can not have an overall vision... ; 2. His multiform social status can't develop this overall vision and leads to an descriptive vision favoring the recensions... ; 3. Despite this absence, Say was one of the first economists to focus on the technical changes despite a conflict between his approach in terms of production and his conclusions focused on the creation of utilities and income distribution and expenses. In conclusion, we shall identify a second "Law of Say": the increasing difficulty of financing innovations and of their developments lead to the cancellation of their disadvantages.À partir de trois textes de Jean-Baptiste Say (Olbie… de 1800, Cours complet… de 1819 et une Lettre à Malthus en 1820 traitant des machines) et d'une approche historique des changements techniques de cette période, nous formulerons trois constats : 1. Say-entrepreneur est au coeur de la révolution industrielle mais ne peut en avoir une vision d'ensemble… ; 2. Son statut social multiforme l'empêche de développer cette vision d'ensemble et le conduit à une vision descriptive privilégiant les recensions… ; 3. Malgré cette absence, Say a été l'un des premiers économistes à s'intéresser aux changements techniques même si une contradiction apparaît entre son approche en terme de production et ses conclusions centrées sur la création d'utilités et sur la répartition des revenus et des charges. En conclusion, on identifiera ainsi une seconde "Loi de Say" : les difficultés croissantes du financement des innovations et leur développement conduisent à l'annulation de leurs inconvénients

Characterization of vorticity in pygmy resonances and soft-dipole modes with two-nucleon transfer reactions

The properties of the two-quasiparticle-like soft E1-modes and PDR have been and are systematically studied with the help of inelastic and electromagnetic experiments which essentially probe the particle-hole components of these vibrations. It is shown that further insight in their characterisation can be achieved with the help of two-nucleon transferreactions, in particular concerning the particle-particle components of the modes, in terms of absolute differential cross sections which take properly into account successive and simultaneous transfer mechanisms corrected for non-orthogonality, able to reproduce the experimental findings at the 10% level. The process $^9$Li$(t,p)^{11}$Li(1$^-$) is discussed, and absolute cross sections predicted.Comment: Typo corrected with respect to previous versio

Gamow-Teller response and its spreading mechanism in doubly magic nuclei

The scope of the paper is to apply a state-of-the-art beyond mean-field model to the description of the Gamow-Teller response in atomic nuclei. This topic recently attracted considerable renewed interest, due, in particular, to the possibility of performing experiments in unstable nuclei. We study the cases of $^{48}$Ca, $^{78}$Ni, $^{132}$Sn and $^{208}$Pb. Our model is based on a fully self-consistent Skyrme Hartree-Fock plus random phase approximation. The same Skyrme interaction is used to calculate the coupling between particles and vibrations, which leads to the mixing of the Gamow-Teller resonance with a set of doorway states and to its fragmentation. We compare our results with available experimental data. The microscopic coupling mechanism is also discussed in some detail.Comment: 27 pages, 10 figure

Inversion Formulas for the Dunkl Intertwining Operator and Its Dual on Spaces of Functions and Distributions

In this paper we prove inversion formulas for the Dunkl intertwining operator $V_k$ and for its dual ${}^tV_k$ and we deduce the expression of the representing distributions of the inverse operators $V_k^{-1}$ and ${}^tV_k^{-1}$, and we give some applications.Comment: This is a contribution to the Special Issue on Dunkl Operators and Related Topics, published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA

Cooper pair transfer in nuclei

The second order DWBA implementation of two-particle transfer direct reactions which includes simultaneous and successive transfer, properly corrected by non-orthogonality effects is tested with the help of controlled nuclear structure and reaction inputs against data spanning the whole mass table, and showed to constitute a quantitative probe of nuclear pairing correlations

Testing two-nucleon transfer reaction mechanism with elementary modes of excitation in exotic nuclei

Nuclear Field Theory of structure and reactions is confronted with observations made on neutron halo dripline nuclei, resulting in the prediction of a novel (symbiotic) mode of nuclear excitation, and on the observation of the virtual effect of the halo phenomenon in the apparently non-halo nucleus $^7$Li. This effect is forced to become real by intervening the virtual process with an external (t,p) field which, combined with accurate predictive abilities concerning the absolute differential cross section, reveals an increase of a factor 2 in the cross section due to the presence of halo ground state correlations, and is essential to reproduce the value of the observed $d \sigma(^7$Li(t,p)$^9$Li)/d$\Omega$.Comment: Submitted to CERN proceedings for the 14th International Conference on Nuclear Reaction mechanisms, Varenna, June 15 - 19, 201