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C. Kwon

Publications and source records attributed to C. Kwon.

4 recordsLinked to original sources
arXiv2007

On the existence of potential landscape in the evolution of complex systems

A recently developed treatment of stochastic processes leads to the construction of a potential landscape for the dynamical evolution of complex systems. Since the existence of a potential function in generic settings has been frequently questioned in literature,herewe study several related theoretical issues that lie at core of the construction. We showthat the novel treatment,via a transformation,is closely related to the symplectic structure that is central in many branches of theoretical physics. Using this insight, we demonstrate an invariant under the transformation. We further explicitly demonstrate, in one-dimensional case, the contradistinction among the new treatment to those of Ito and Stratonovich, as well as others.Our results strongly suggest that the method from statistical physics can be useful in studying stochastic, complex systems in general.

q-bio.QM↗
arXiv2006

Equivalence of operator-splitting schemes for the integration of the Langevin equation

We investigate the equivalence of different operator-splitting schemes for the integration of the Langevin equation. We consider a specific problem, so called the directed percolation process, which can be extended to a wider class of problems. We first give a compact mathematical description of the operator-splitting method and introduce two typical splitting schemes that will be useful in numerical studies. We show that the two schemes are essentially equivalent through the map that turns out to be an automorphism. An associated equivalent class of operator-splitting integrations is also defined by generalizing the specified equivalence.

cond-mat.stat-mech↗
arXiv1996

Giant Magneto-Resistance in Nd$_{0.7}$Sr$_{0.3}$MnO$_3$ at Optical Frequencies

The optical properties of Nd$_{0.7}$Sr$_{0.3}$MnO$_3$ thin films have been studied from 5 meV to 25 meV and from 0.25 eV to 3 eV, at temperatures from 15 K to 300 K and magnetic fields up to 8.9 T. A large transfer of spectral weight from high energy to low energy occurs as the temperature is decreased below 180 K, where the dc resistivity peaks, or as the magnetic field is increased. The optical data are found to be consistent with models that include both the double exchange interaction and the dynamic Jahn-Teller effect on the Mn$^{3+}$ e$_g$ levels.

cond-mat↗