1,069 research outputs found
Quantum theory of non-abelian differential forms and link polynomials
A topological quantum field theory of non-abelian differential forms is
investigated from the point of view of its possible applications to description
of polynomial invariants of higher-dimensional two-component links. A
path-integral representation of the partition function of the theory, which is
a highly on-shell reducible system, is obtained in the framework of the
antibracket-antifield formalism of Batalin and Vilkovisky. The quasi-monodromy
matrix, giving rise to corresponding skein relations, is formally derived in a
manifestly covariant non-perturbative manner.Comment: 18 pages, REVISED: minor improvement
SU(2) and the Kauffman bracket
A direct relationship between the (non-quantum) group SU(2) and the Kauffman
bracket in the framework of Chern-Simons theory is explicitly shown.Comment: 5 page
Three-dimensional topological quantum field theory of Witten type
Description of two three-dimensional topological quantum field theories of Witten type as twisted supersymmetric theories is presented. Low-energy effective action and a corresponding topological invariant of three-dimensional manifolds are considered
Spin-selective localization due to intrinsic spin-orbit coupling
We study spin-dependent diffusive transport in the presence of a tunable
spin-orbit (SO) interaction in a two-dimensional electron system. The spin
precession of an electron in the SO coupling field is expressed in terms of a
covariant curvature, affecting the quantum interference between different
electronic trajectories. Controlling this curvature field by modulating the SO
coupling strength and its gradients by, e.g., electric or elastic means, opens
intriguing possibilities for exploring spin-selective localization physics. In
particular, applying a weak magnetic field allows the control of the electron
localization independently for two spin directions, with the spin-quantization
axis that could be "engineered" by appropriate SO interaction gradients.Comment: 7 pages, 1 figur
"Microscopic" approach to the Ricci dark energy
A derivation of the Ricci dark energy from quantum field theory of
fluctuating "matter" fields in a classical gravitational background is
presented. The coupling to the dark energy, the parameter 'a', is estimated in
the framework of our formalism, and qualitatively it appears to be within
observational expectations.Comment: 7 page
Gauge-Invariant Formulation of Spin-Current-Density Functional Theory
Spin-currents and non-abelian gauge potentials in electronic systems can be
treated by spin-current-density functional theory, whose main input is the
exchange-correlation (xc) energy expressed as a functional of spin-currents.
Constructing a functional of spin currents that is invariant under
U(1)SU(2) transformations is a long-standing challenge. We solve the
problem by expressing the energy as a functional of a new variable we call
"invariant vorticity". As an illustration we construct the xc energy functional
for a two-dimensional electron gas with linear spin-orbit coupling and show
that it is proportional to the fourth power of the spin current.Comment: 8 pages, 3 figures, submitte
Decay and Isomeric Properties of Neutron-Rich Ca and Sc Isotopes
The isomeric and -decay properties of neutron-rich Sc and
Ca nuclei near neutron number =32 are reported, and the low-energy
level schemes of Sc and Ti are presented. The low-energy
level structures of the Sc isotopes are discussed in terms of the
coupling of the valence proton to states in the corresponding
Ca cores. Implications with respect to the robustness of the =32
subshell closure are discussed, as well as the repercussions for a possible
=34 subshell closure.Comment: 17 pages, 17 figures, accepted to Phys. Rev.
4-Dimensional BF Theory as a Topological Quantum Field Theory
Starting from a Lie group G whose Lie algebra is equipped with an invariant
nondegenerate symmetric bilinear form, we show that 4-dimensional BF theory
with cosmological term gives rise to a TQFT satisfying a generalization of
Atiyah's axioms to manifolds equipped with principal G-bundle. The case G =
GL(4,R) is especially interesting because every 4-manifold is then naturally
equipped with a principal G-bundle, namely its frame bundle. In this case, the
partition function of a compact oriented 4-manifold is the exponential of its
signature, and the resulting TQFT is isomorphic to that constructed by Crane
and Yetter using a state sum model, or by Broda using a surgery presentation of
4-manifolds.Comment: 15 pages in LaTe
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