5,198 research outputs found
Algebraic methods for dynamic systems
Algebraic methods for application to dynamic control system
An effective thermodynamic potential from the instanton with Polyakov-loop contributions
We derive an effective thermodynamic potential (Omega_eff) at finite
temperature (T>0) and zero quark-chemical potential (mu_R=0), using the
singular-gauge instanton solution and Matsubara formula for N_c=3 and N_f=2 in
the chiral limit. The momentum-dependent constituent-quark mass is also
obtained as a function of T, employing the Harrington-Shepard caloron solution
in the large-N_c limit. In addition, we take into account the imaginary quark
chemical potential mu_I = A_4, translated as the traced Polayakov-loop (Phi) as
an order parameter for the Z(N_c) symmsetry, characterizing the confinement
(intact) and deconfinement (spontaneously broken) phases. As a result, we
observe the crossover of the chiral (chi) order parameter sigma^2 and Phi. It
also turns out that the critical temperature for the deconfinment phase
transition, T^Z_c is lowered by about (5-10)% in comparison to the case with a
constant constituent-quark mass. This behavior can be understood by
considerable effects from the partial chiral restoration and nontrivial QCD
vacuum on Phi. Numerical calculations show that the crossover transitions occur
at (T^chi_c,T^Z_c) ~ (216,227) MeV.Comment: 15 pages, 7 figure
Reference Distorted Prices
I show that when consumers (mis)perceive prices relative to reference prices,
budgets turn out to be soft, prices tend to be lower and the average quality of
goods sold decreases. These observations provide explanations for decentralized
purchase decisions, for people being happy with a purchase even when they have
paid their evaluation, and for why trade might affect high quality local firms
'unfairly'
Thermodynamic phase transitions for Pomeau-Manneville maps
We study phase transitions in the thermodynamic description of
Pomeau-Manneville intermittent maps from the point of view of infinite ergodic
theory, which deals with diverging measure dynamical systems. For such systems,
we use a distributional limit theorem to provide both a powerful tool for
calculating thermodynamic potentials as also an understanding of the dynamic
characteristics at each instability phase. In particular, topological pressure
and Renyi entropy are calculated exactly for such systems. Finally, we show the
connection of the distributional limit theorem with non-Gaussian fluctuations
of the algorithmic complexity proposed by Gaspard and Wang [Proc. Natl. Acad.
Sci. USA 85, 4591 (1988)].Comment: 5 page
Thermoelectric power of Ba(Fe1-xRux)2As2 and Ba(Fe1-xCox)2As2: possible changes of Fermi surface with and without changes in electron count
Temperature-dependent, in-plane, thermoelectric power (TEP) data are
presented for Ba(Fe1-xRux)2As2 (0 < x < 0.36) single crystals. The previously
outlined x - T phase diagram for this system is confirmed. The analysis of TEP
evolution with Ru-doping suggests significant changes in the electronic
structure, correlations and/or scattering occurring near ~7% and ~30% of
Ru-doping levels. These results are compared with an extended set of TEP data
for the electron-doped Ba(Fe1-xCox)2As2 series
Dynamic Phase Transitions in Cell Spreading
We monitored isotropic spreading of mouse embryonic fibroblasts on
fibronectin-coated substrates. Cell adhesion area versus time was measured via
total internal reflection fluorescence microscopy. Spreading proceeds in
well-defined phases. We found a power-law area growth with distinct exponents
a_i in three sequential phases, which we denote basal (a_1=0.4+-0.2), continous
(a_2=1.6+-0.9) and contractile (a_3=0.3+-0.2) spreading. High resolution
differential interference contrast microscopy was used to characterize local
membrane dynamics at the spreading front. Fourier power spectra of membrane
velocity reveal the sudden development of periodic membrane retractions at the
transition from continous to contractile spreading. We propose that the
classification of cell spreading into phases with distinct functional
characteristics and protein activity patterns serves as a paradigm for a
general program of a phase classification of cellular phenotype. Biological
variability is drastically reduced when only the corresponding phases are used
for comparison across species/different cell lines.Comment: 4 pages, 5 figure
NMR investigation of vortex dynamics in Ba(Fe0.93Rh0.07)2As2 superconductor
75As NMR spin-lattice relaxation (1/T1) and spin-echo decay (1/T2) rate
measurements were performed in a single crystal of Ba(Fe0.93Rh0.07)2As2
superconductor. Below the superconducting transition temperature Tc, when the
magnetic field H is applied along the c axes, a peak in both relaxation rates
is observed. Remarkably that peak is suppressed for H || ab. Those maxima in
1/T1 and 1/T2 have been ascribed to the flux lines lattice motions and the
corresponding correlation times and pinning energy barriers have been derived
on the basis of an heuristic model. Further information on the flux lines
motion was derived from the narrowing of 75As NMR linewidth below Tc and found
to be consistent with that obtained from 1/T2 measurements. All the
experimental results are described in the framework of thermally activated
vortices motions.Comment: 8 pages, 11 figure
On the informational content of wage offers
This article investigates signaling and screening roles of wage offers in a single-play matching model with two-sided unobservable characteristics. It generates the following predictions as matching equilibrium outcomes: (i) âgoodâ jobs offer premia if âhigh-qualityâ worker population is large; (ii) âbadâ jobs pay compensating differentials if the proportion of âgoodâ jobs to âlow-qualityâ workers is large; (iii) all firms may offer a pooling wage in markets dominated by âhigh-qualityâ workers and firms; or (iv) Greshamâs Law prevails: âgoodâ types withdraw if âbadâ types dominate the population. The screening/signaling motive thus has the potential of explaining a variety of wage patterns
Impact of Technology on Meat Safety
Innovations and new technologies tend to create apprehension among consumers who are not familiar with the technologies and their mode of action. This case currently exists regarding the use of hormones, antibiotics and other feed additives in livestock production. The purpose of this fact sheet is to familiarize consumers with some of the products of technology that are currently utilized in the production of meat animals and to provide an evaluation of how these products impact the safety of meat and meat products
New Physics with earliest LHC data
We investigate which new physics models could be discovered in the first year of the LHC. Such a âSupermodelâ is a new physics scenario for which the LHC sensitivity with only 10 pbâ1 useful luminosity is greater than that of the
Tevatron with 10 fbâ1. The simplest supermodels involve s-channel resonances in the quark-antiquark and especially in the quark-quark channels. We concentrate on easily visible final states with small standard model backgrounds, and suggest simple searches, besides those for Z
states, which could discover new physics in
early LHC data
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