arXiv subjects

Jochen Rau

Publications and source records attributed to Jochen Rau.

21 records · Page 2Linked to original sources

arXiv1996

Renormalization by Projection: On the Equivalence of the Bloch-Feshbach Formalism and Wilson's Renormalization

We employ projection operator techniques in Hilbert space to derive a continuous sequence of effective Hamiltonians which describe the dynamics on successively larger length scales. We show for the case of ϕ^4 theory that the masses and couplings in these effective Hamiltonians vary in accordance with 1-loop renormalization group equations. This is evidence for an intimate connection between Wilson's renormalization and the venerable Bloch-Feshbach formalism.

hep-th↗

arXiv1994

Ballistic Transport Through Chaotic Cavities: Can Parametric Correlations and the Weak Localization Peak be Described by a Brownian Motion Model?

A Brownian motion model is devised on the manifold of S-matrices, and applied to the calculation of conductance-conductance correlations and of the weak localization peak. The model predicts that (i) the correlation function in $B$ has the same shape and width as the weak localization peak; (ii) the functions behave as $\propto 1-{\cal O}(B^2)$, thus excluding a linear line shape; and (iii) their width increases as the square root of the number of channels in the leads. Some of these predictions agree with experiment and with other calculations only in the limit of small $B$ and a large number of channels.

cond-mat↗

arXiv1994

Pair Production in the Quantum Boltzmann Equation

A source term in the quantum Boltzmann equation, which accounts for the spontaneous creation of $e^+e^-$-pairs in external electric fields, is derived from first principles and evaluated numerically. Careful analysis of time scales reveals that this source term is generally non-Markovian. This implies in particular that there may be temporary violations of the $H$-theorem.

hep-ph↗