scholarly journals Publisher’s Note: Static quark-antiquark free energy and the running coupling at finite temperature [Phys. Rev. DPRVDAQ0556-282170, 074505 (2004)]

2005 ◽  
Vol 72 (5) ◽  
Author(s):  
O. Kaczmarek ◽  
F. Karsch ◽  
F. Zantow ◽  
P. Petreczky
2004 ◽  
Vol 70 (7) ◽  
Author(s):  
O. Kaczmarek ◽  
F. Karsch ◽  
F. Zantow ◽  
P. Petreczky

2009 ◽  
Author(s):  
Alexei Bazavov ◽  
Peter Petreczky ◽  
Alexander Velytsky

2002 ◽  
Vol 17 (06n07) ◽  
pp. 790-793 ◽  
Author(s):  
V. V. NESTERENKO ◽  
G. LAMBIASE ◽  
G. SCARPETTA

The basic results in calculations of the thermodynamic functions of electromagnetic field in the background of a dilute dielectric ball at zero and finite temperature are presented. Summation over the angular momentum values is accomplished in a closed form by making use of the addition theorem for the relevant Bessel functions. The behavior of the thermodynamic characteristics in the low and high temperature limits is investigated. The T3-term in the low temperature expansion of the free energy is recovered (this term has been lost in our previous calculations).


Author(s):  
Vasily Bulatov ◽  
Wei Cai

Free energy is of central importance for understanding the properties of physical systems at finite temperatures. While in the zero temperature limit the system should evolve to a state of minimum energy (Section 2.3), this is not necessarily the case at a finite temperature. When an open system exchanges energy with the outside world (a thermostat) and maintains a constant temperature, its evolution proceeds towards minimizing its free energy. For example, a crystal turns into a liquid when the temperature exceeds its melting temperature precisely because the free energy of the liquid state becomes lower than that of the crystalline state. In the context of dislocation simulations, free energy is all important when one has to decide which of the possible core configurations the dislocation is likely to adopt at a given temperature.


2009 ◽  
Vol 87 (10) ◽  
pp. 1322-1337 ◽  
Author(s):  
Hans Martin Senn ◽  
Johannes Kästner ◽  
Jürgen Breidung ◽  
Walter Thiel

We report potential-energy and free-energy data for three enzymatic reactions: carbon–halogen bond formation in fluorinase, hydrogen abstraction from camphor in cytochrome P450cam, and chorismate-to-prephenate Claisen rearrangement in chorismate mutase. The results were obtained by combined quantum mechanics/molecular mechanics (QM/MM) optimizations and two types of QM/MM free-energy simulations (free-energy perturbation and umbrella sampling) using semi-empirical or density-functional QM methods. Based on these results and our previously published free-energy data on electrophilic substitution in para-hydroxybenzoate hydroxylase, we discuss the importance of finite-temperature effects in the chemical step of enzyme reactions. We find that the entropic contribution to the activation barrier is generally rather small, usually of the order of 5 kJ mol–1 or less, consistent with the notion that enzymes bind and pre-organize the reactants in the active site. A somewhat larger entropic contribution is encountered in the case of chorismate mutase where the pericyclic transition state is intrinsically more rigid than the chorismate reactant (also in the enzyme). The present results suggest that barriers from QM/MM geometry optimization may often be close to free-energy barriers for the chemical step in enzymatic reactions.


2013 ◽  
Vol 27 (08) ◽  
pp. 1350028 ◽  
Author(s):  
NABYENDU DAS

Here a recently observed weak first order transition in doped SrTiO 3 [Taniguchi, Itoh and Yagi, Phys. Rev. Lett.99, 017602 (2007)] is argued to be a consequence of the coupling between strain and order parameter fluctuations. Starting with a semi-microscopic action, and using renormalization group equations for vertices, we write the free energy of such a system. This fluctuation renormalized free energy is then used to discuss the possibility of first order transition at zero temperature as well as at finite temperature. An asymptotic analysis predicts small but a finite discontinuity in the order parameter near a mean field quantum critical point at zero temperature. In case of finite temperature transition, near quantum critical point such a possibility is found to be extremely weak. Results are in accord with some experimental findings on quantum paraelectrics such as SrTiO 3 and KTaO 3.


2014 ◽  
Vol 931 ◽  
pp. 607-611
Author(s):  
Taesoo Song ◽  
Su Houng Lee ◽  
Kenji Morita ◽  
Che Ming Ko

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1066
Author(s):  
Róbinson J. Acosta Diaz ◽  
Christian D. Rodríguez-Camargo ◽  
Nami F. Svaiter

We consider field theory formulation for directed polymers and interfaces in the presence of quenched disorder. We write a series representation for the averaged free energy, where all the integer moments of the partition function of the model contribute. The structure of field space is analysed for polymers and interfaces at finite temperature using the saddle-point equations derived from each integer moments of the partition function. For the case of an interface we obtain the wandering exponent ξ = ( 4 − d ) / 2 , also obtained by the conventional replica method for the replica symmetric scenario.


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