28,805 research outputs found
Extreme Value distribution for singular measures
In this paper we perform an analytical and numerical study of Extreme Value
distributions in discrete dynamical systems that have a singular measure. Using
the block maxima approach described in Faranda et al. [2011] we show that,
numerically, the Extreme Value distribution for these maps can be associated to
the Generalised Extreme Value family where the parameters scale with the
information dimension. The numerical analysis are performed on a few low
dimensional maps. For the middle third Cantor set and the Sierpinskij triangle
obtained using Iterated Function Systems, experimental parameters show a very
good agreement with the theoretical values. For strange attractors like Lozi
and H\`enon maps a slower convergence to the Generalised Extreme Value
distribution is observed. Even in presence of large statistics the observed
convergence is slower if compared with the maps which have an absolute
continuous invariant measure. Nevertheless and within the uncertainty computed
range, the results are in good agreement with the theoretical estimates
Coherent States Measurement Entropy
Coherent states (CS) quantum entropy can be split into two components. The
dynamical entropy is linked with the dynamical properties of a quantum system.
The measurement entropy, which tends to zero in the semiclassical limit,
describes the unpredictability induced by the process of a quantum approximate
measurement. We study the CS--measurement entropy for spin coherent states
defined on the sphere discussing different methods dealing with the time limit
. In particular we propose an effective technique of computing
the entropy by iterated function systems. The dependence of CS--measurement
entropy on the character of the partition of the phase space is analysed.Comment: revtex, 22 pages, 14 figures available upon request (e-mail:
[email protected]). Submitted to J.Phys.
Homology of E_n Ring Spectra and Iterated THH
We describe an iterable construction of THH for an E_n ring spectrum. The
reduced version is an iterable bar construction and its n-th iterate gives a
model for the shifted cotangent complex at the augmentation, representing
reduced topological Quillen homology of an augmented E_n algebra.Comment: Some additional exposition added. Minor correction
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