2,504 research outputs found

    Refined analytic torsion for twisted de Rham complexes

    Full text link
    Let EE be a flat complex vector bundle over a closed oriented odd dimensional manifold MM endowed with a flat connection βˆ‡\nabla. The refined analytic torsion for (M,E)(M,E) was defined and studied by Braverman and Kappeler. Recently Mathai and Wu defined and studied the analytic torsion for the twisted de Rham complex with an odd degree closed differential form HH, other than one form, as a flux and with coefficients in EE. In this paper we generalize the construction of the refined analytic torsion to the twisted de Rham complex. We show that the refined analytic torsion of the twisted de Rham complex is independent of the choice of the Riemannian metric on MM and the Hermitian metric on EE. We also show that the twisted refined analytic torsion is invariant (under a natural identification) if HH is deformed within its cohomology class. We prove a duality theorem, establishing a relationship between the twisted refined analytic torsion corresponding to a flat connection and its dual. We also define the twisted analogue of the Ray-Singer metric and calculate the twisted Ray-Singer metric of the twisted refined analytic torsion. In particular we show that in case that the Hermtitian connection is flat, the twisted refined analytic torsion is an element with the twisted Ray-Singer norm one.Comment: 30 Page

    Twisted Cappell-Miller holomorphic and analytic torsions

    Full text link
    Recently, Cappell and Miller extended the classical construction of the analytic torsion for de Rham complexes to coupling with an arbitrary flat bundle and the holomorphic torsion for βˆ‚Λ‰\bar{\partial}-complexes to coupling with an arbitrary holomorphic bundle with compatible connection of type (1,1)(1,1). Cappell and Miller studied the properties of these torsions, including the behavior under metric deformations. On the other hand, Mathai and Wu generalized the classical construction of the analytic torsion to the twisted de Rham complexes with an odd degree closed form as a flux and later, more generally, to the Z2\mathbb{Z}_2-graded elliptic complexes. Mathai and Wu also studied the properties of analytic torsions for the Z2\mathbb{Z}_2-graded elliptic complexes, including the behavior under metric and flux deformations. In this paper we define the Cappell-Miller holomorphic torsion for the twisted Dolbeault-type complexes and the Cappell-Miller analytic torsion for the twisted de Rham complexes. We obtain variation formulas for the twisted Cappell-Miller holomorphic and analytic torsions under metric and flux deformations.Comment: 21 page

    Strategic environmental assessment for the utilisation of offshore wind energy

    Get PDF
    • …
    corecore