106,191 research outputs found
Large-N analysis of (2+1)-dimensional Thirring model
We analyze -dimensional vector-vector type four-Fermi interaction
(Thirring) model in the framework of the expansion. By solving the
Dyson-Schwinger equation in the large- limit, we show that in the
two-component formalism the fermions acquire parity-violating mass dynamically
in the range of the dimensionless coupling , . The symmetry
breaking pattern is, however, in a way to conserve the overall parity of the
theory such that the Chern-Simons term is not induced at any orders in .
turns out to be a non-perturbative UV-fixed point in . The
function is calculated to be
near the fixed point, and the UV-fixed point and the function are shown
exact in the expansion.Comment: 14 pages Latex. (Revised version: some changes have been made and
references added.) To appear in Phys. Rev. D, SNUTP 93-4
Eta invariants with spectral boundary conditions
We study the asymptotics of the heat trace \Tr\{fPe^{-tP^2}\} where is
an operator of Dirac type, where is an auxiliary smooth smearing function
which is used to localize the problem, and where we impose spectral boundary
conditions. Using functorial techniques and special case calculations, the
boundary part of the leading coefficients in the asymptotic expansion is found.Comment: 19 pages, LaTeX, extended Introductio
Comment on "Spectroscopic Evidence for Multiple Order Parameter Components in the Heavy Fermion Superconductor CeCoIn"
Recently, Rourke et al. reported point-contact spectroscopy results on the
heavy-fermion superconductor CeCoIn [1]. They obtained conductance spectra
on the c-axis surfaces of CeCoIn single crystals. Their major claims are
two-fold: CeCoIn has i) d-wave pairing symmetry and ii) two coexisting
order parameter components. In this Comment, we show that these claims are not
warranted by the data presented. [1] Rourke et al., Phys. Rev. Lett. 94, 107005
(2005).Comment: accepted for publication in Phys. Rev. Lett., final for
Universal curvature identities
We study scalar and symmetric 2-form valued universal curvature identities.
We use this to establish the Gauss-Bonnet theorem using heat equation methods,
to give a new proof of a result of Kuz'mina and Labbi concerning the
Euler-Lagrange equations of the Gauss-Bonnet integral, and to give a new
derivation of the Euh-Park-Sekigawa identity.Comment: 11 page
- …