61 research outputs found
Universal geometric entanglement close to quantum phase transitions
Under successive Renormalization Group transformations applied to a quantum
state of finite correlation length , there is typically a
loss of entanglement after each iteration. How good it is then to replace
by a product state at every step of the process? In this paper we
give a quantitative answer to this question by providing first analytical and
general proofs that, for translationally invariant quantum systems in one
spatial dimension, the global geometric entanglement per region of size diverges with the correlation length as
close to a quantum critical point with central charge , where is
a cut-off at short distances. Moreover, the situation at criticality is also
discussed and an upper bound on the critical global geometric entanglement is
provided in terms of a logarithmic function of .Comment: 4 pages, 3 figure
Large-Mass Ultra-Low Noise Germanium Detectors: Performance and Applications in Neutrino and Astroparticle Physics
A new type of radiation detector, a p-type modified electrode germanium
diode, is presented. The prototype displays, for the first time, a combination
of features (mass, energy threshold and background expectation) required for a
measurement of coherent neutrino-nucleus scattering in a nuclear reactor
experiment. The device hybridizes the mass and energy resolution of a
conventional HPGe coaxial gamma spectrometer with the low electronic noise and
threshold of a small x-ray semiconductor detector, also displaying an intrinsic
ability to distinguish multiple from single-site particle interactions. The
present performance of the prototype and possible further improvements are
discussed, as well as other applications for this new type of device in
neutrino and astroparticle physics (double-beta decay, neutrino magnetic moment
and WIMP searches).Comment: submitted to Phys. Rev.
Modeling and forecasting daily electricity load curves: a hybrid approach
We propose a hybrid approach for the modeling and the short-term forecasting of electricity loads. Two building blocks of our approach are (1) modeling the overall trend and seasonality by fitting a generalized additive model to the weekly averages of the load and (2) modeling the dependence structure across consecutive daily loads via curve linear regression. For the latter, a new methodology is proposed for linear regression with both curve response and curve regressors. The key idea behind the proposed methodology is dimension reduction based on a singular value decomposition in a Hilbert space, which reduces the curve regression problem to several ordinary (i.e., scalar) linear regression problems. We illustrate the hybrid method using French electricity loads between 1996 and 2009, on which we also compare our method with other available models including the Électricité de France operational model. Supplementary materials for this article are available online
Mineralogical and trace element composition of clay-sized fractions from Albian siliciclastic rocks (Oliete Basin, NE Spain)
Os gêneros do métier docente: a linguagem como instrumentalização do trabalho do professor
Nutritional ecology and ecological immunology in degus: Does early nutrition affect the postnatal development of the immune function?
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