24,327 research outputs found
Statistical mechanics derivation of hydrodynamic boundary conditions: the diffusion equation
Considering the example of interacting Brownian particles we present a linear
response derivation of the boundary condition for the corresponding
hydrodynamic description (the diffusion equation). This requires us to identify
a non-analytic structure in a microscopic relaxation kernel connected to the
frequency dependent penetration length familiar for diffusive processes, and
leads to a microscopic definition of the position where the hydrodynamic
boundary condition has to be applied. Corrections to the hydrodynamic limit are
obtained and we derive general amplitudes of spatially and temporally long
ranged states in the considered diffusive system.Comment: 15 pages; slightly revised and shortened version; J. Phys.: Condens.
Matter in prin
Non--Newtonian viscosity of interacting Brownian particles: comparison of theory and data
A recent first-principles approach to the non-linear rheology of dense
colloidal suspensions is evaluated and compared to simulation results of
sheared systems close to their glass transitions. The predicted scenario of a
universal transition of the structural dynamics between yielding of glasses and
non-Newtonian (shear-thinning) fluid flow appears well obeyed, and calculations
within simplified models rationalize the data over variations in shear rate and
viscosity of up to 3 decades.Comment: 6 pages, 2 figures; J. Phys. Condens. Matter to be published (Jan.
2003
The Conductance of a Perfect Thin Film with Diffuse Surface Scattering
The conductance of thin films with diffusive surface scattering was solved
semi-classically by Fuchs and Sondheimer. However, when the intrinsic electron
mean free path is very large or infinite their conductance diverges. In this
letter a simple diffraction picture is presented. It yields a conductance which
corresponds to a limiting mean free path. PACS: 73.50.-h, 73.50.Bk, 73.23.-b,
73.25.+i, B14
The Moderating Role of Context in Determining Unethical Managerial Behavior: A Case Survey
We examine the moderating role of the situational and organizational contexts in determining unethical managerial behavior, applying the case-survey methodology. On the basis of a holistic, multiple-antecedent perspective, we hypothesize that two key constructs, moral intensity and situational strength, help explain contextual moderating effects on relationships between managers’ individual characteristics and unethical behavior. Based on a quantitative analysis of 52 case studies describing occurrences of real-life unethical conduct, we find empirical support for the hypothesized contextual moderating effects of moral intensity and situational strength. By examining these complex contextual moderators, we aim to contribute to organizational ethics research as we shed light on the critical role that context may play in influencing unethical managerial behavior
Schnabl's L_0 Operator in the Continuous Basis
Following Schnabl's analytic solution to string field theory, we calculate
the operators for a scalar field in the
continuous basis. We find an explicit and simple expression for them
that further simplifies for their sum, which is block diagonal in this basis.
We generalize this result for the bosonized ghost sector, verify their
commutation relation and relate our expressions to wedge state representations.Comment: 1+16 pages. JHEP style. Typos correcte
S_4-symmetry of 6j-symbols and Frobenius-Schur indicators in rigid monoidal C^*-categories
We show that a left-rigid monoidal C^*-category with irreducible monoidal
unit is also a sovereign and spherical category. Defining a Frobenius-Schur
type indicator we obtain selection rules for the fusion coefficients of
irreducible objects. As a main result we prove S_4-invariance of 6j-symbols in
such a category.Comment: 21 pages + 16 pages with figures; LaTeX2e plus macro package XYpic;
file with included pictures available as
http://www.desy.de/~jfuchs/s4/s4.ps.g
- …