Probing subglass relaxation in polymers via a geometric representation of probabilities, observables, and relaxation modes for discrete stochastic systems

Boulougouris, GC; Theodorou, DN

dc.contributor.author	Boulougouris, GC	en
dc.contributor.author	Theodorou, DN	en
dc.date.accessioned	2014-03-01T01:31:42Z
dc.date.available	2014-03-01T01:31:42Z
dc.date.issued	2009	en
dc.identifier.issn	0021-9606	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19898
dc.subject	eigenvalues and eigenfunctions	en
dc.subject	free energy	en
dc.subject	polymers	en
dc.subject	stochastic processes	en
dc.subject.classification	Physics, Atomic, Molecular & Chemical	en
dc.subject.other	Biological systems	en
dc.subject.other	Dynamics	en
dc.subject.other	Polystyrenes	en
dc.subject.other	Stochastic systems	en
dc.subject.other	Atactic polystyrenes	en
dc.subject.other	Configuration spaces	en
dc.subject.other	Discrete state	en
dc.subject.other	Discrete stochastic systems	en
dc.subject.other	Eigenvectors	en
dc.subject.other	Ensemble averages	en
dc.subject.other	Euclidean spaces	en
dc.subject.other	Geometric representations	en
dc.subject.other	Long-time dynamics	en
dc.subject.other	Low energy regions	en
dc.subject.other	Macroscopic properties	en
dc.subject.other	Molecular mechanisms	en
dc.subject.other	Non equilibriums	en
dc.subject.other	Phenyl groups	en
dc.subject.other	Relaxation modes	en
dc.subject.other	Segmental relaxations	en
dc.subject.other	Simple expressions	en
dc.subject.other	State probabilities	en
dc.subject.other	Subglass relaxations	en
dc.subject.other	Time correlation functions	en
dc.subject.other	Time evolution operators	en
dc.subject.other	Space probes	en
dc.subject.other	9 alpha,11 alpha,15 alpha trihydroxy 16 phenoxy 17,18,19,20 tetranorprosta 4,5,13 trienoic acid	en
dc.subject.other	9 alpha,11 alpha,15 alpha-trihydroxy-16-phenoxy-17,18,19,20-tetranorprosta-4,5,13-trienoic acid	en
dc.subject.other	polymer	en
dc.subject.other	prostaglandin derivative	en
dc.subject.other	article	en
dc.subject.other	chemistry	en
dc.subject.other	heat	en
dc.subject.other	Monte Carlo method	en
dc.subject.other	probability	en
dc.subject.other	statistics	en
dc.subject.other	Hot Temperature	en
dc.subject.other	Monte Carlo Method	en
dc.subject.other	Polymers	en
dc.subject.other	Probability	en
dc.subject.other	Prostaglandins, Synthetic	en
dc.subject.other	Stochastic Processes	en
dc.title	Probing subglass relaxation in polymers via a geometric representation of probabilities, observables, and relaxation modes for discrete stochastic systems	en
heal.type	journalArticle	en
heal.identifier.primary	10.1063/1.3063118	en
heal.identifier.secondary	http://dx.doi.org/10.1063/1.3063118	en
heal.identifier.secondary	044905	en
heal.language	English	en
heal.publicationDate	2009	en
heal.abstract	The dynamics of many physical, chemical, and biological systems can be reduced to a succession of infrequent transitions in a network of discrete states representing low energy regions in configuration space. This enables accessing long-time dynamics and predicting macroscopic properties. Here we develop a new, perfectly general statistical mechanical/geometric formulation that expresses both state probabilities and all observables in the same Euclidean space, spanned by the eigenvectors of the symmetrized time evolution operator. Our formalism leads to simple expressions for nonequilibrium and equilibrium ensemble averages, variances, and time correlation functions of any observable and allows a rigorous decomposition of the dynamics into relaxation modes. Applying it to subglass segmental relaxation in atactic polystyrene up to times on the order of 10 μs, we probe the molecular mechanism of the γ and δ processes and unequivocally identify the δ process with rotation of a single phenyl group around its stem. © 2009 American Institute of Physics.	en
heal.publisher	AMER INST PHYSICS	en
heal.journalName	Journal of Chemical Physics	en
dc.identifier.doi	10.1063/1.3063118	en
dc.identifier.isi	ISI:000262965000044	en
dc.identifier.volume	130	en
dc.identifier.issue	4	en