Twisted index theory on good orbifolds, II: Fractional quantum numbers

Date

2001

Authors

Marcolli, M.
Varghese, M.

Editors

Advisors

Journal Title

Journal ISSN

Volume Title

Type:

Journal article

Citation

Communications in Mathematical Physics, 2001; 217(1):55-87

Statement of Responsibility

Matilde Marcolli, Varghese Mathai

Conference Name

Abstract

This paper uses techniques in noncommutative geometry as developed by Alain Connes [Co2], in order to study the twisted higher index theory of elliptic operators on orbifold covering spaces of compact good orbifolds, which are invariant under a projective action of the orbifold fundamental group, continuing our earlier work [MM]. We also compute the range of the higher cyclic traces on K-theory for cocompact Fuchsian groups, which is then applied to determine the range of values of the Connes–Kubo Hall conductance in the discrete model of the quantum Hall effect on the hyperbolic plane, generalizing earlier results in [Bel+E+S], [CHMM]. The new phenomenon that we observe in our case is that the Connes–Kubo Hall conductance has plateaux at integral multiples of a fractional valued topological invariant, namely the orbifold Euler characteristic. Moreover the set of possible fractions has been determined, and is compared with recently available experimental data. It is plausible that this might shed some light on the mathematical mechanism responsible for fractional quantum numbers.

School/Discipline

Dissertation Note

Provenance

Description

The original publication can be found at www.springerlink.com

Access Status

Rights

© Springer-Verlag 2001

License

Grant ID

Call number

Persistent link to this record