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Related papers: Curved noncommutative torus and Gauss--Bonnet

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We introduce a family of spectral triples that describe the curved noncommutative two-torus. The relevant family of new Dirac operators is given by rescaling one of two terms in the flat Dirac operator. We compute the dressed scalar…

Quantum Algebra · Mathematics 2018-06-04 Ludwik Dabrowski , Andrzej Sitarz

We give a local expression for the {\it scalar curvature} of the noncommutative two torus $ A_{\theta} = C(\mathbb{T}_{\theta}^2)$ equipped with an arbitrary translation invariant complex structure and Weyl factor. This is achieved by…

Quantum Algebra · Mathematics 2011-10-18 Farzad Fathizadeh , Masoud Khalkhali

Our understanding of the notion of curvature in a noncommutative setting has progressed substantially in the past ten years. This new episode in noncommutative geometry started when a Gauss-Bonnet theorem was proved by Connes and Tretkoff…

Quantum Algebra · Mathematics 2020-02-11 Farzad Fathizadeh , Masoud Khalkhali

In this paper we give a proof of the Gauss-Bonnet theorem of Connes and Tretkoff for noncommutative two tori $\mathbb{T}_{\theta}^2$ equipped with an arbitrary translation invariant complex structure. More precisely, we show that for any…

Operator Algebras · Mathematics 2011-04-18 Farzad Fathizadeh , Masoud Khalkhali

In this paper we investigate the curvature of conformal deformations by noncommutative Weyl factors of a flat metric on a noncommutative 2-torus, by analyzing in the framework of spectral triples functionals associated to perturbed…

Quantum Algebra · Mathematics 2013-10-15 Alain Connes , Henri Moscovici

We prove the analogue of the Riemann-Roch formula for the noncommutative two torus $ A_{\theta} = C(\mathbb{T}_{\theta}^2)$ equipped with an arbitrary translation invariant complex structure and a Weyl factor represented by a positive…

Quantum Algebra · Mathematics 2015-06-16 Masoud Khalkhali , Ali Moatadelro

We derive an explicit formula for the scalar curvature over a two-torus with a Dirac operator conformally rescaled by a globally diagonalizable matrix. We show that the Gauss-Bonnet theorem holds and extend the result to all Riemann…

Quantum Algebra · Mathematics 2018-06-20 Masoud Khalkhali , Andrzej Sitarz

We explicitly compute the spectral metric, torsion and Einstein tensors for a nontrivial spectral triple on a noncommutative torus, with the Dirac operator related to the fully equivariant Dirac by a partial conformal rescaling (as…

Quantum Algebra · Mathematics 2026-03-12 Deeponjit Bose , Andrzej Sitarz

We consider a generic curved non-commutative torus extending the notion of conformally deformed non-commutative torus from \cite{Connes-Tretkoff}. In general, a curved non-commutative torus is no longer represented by a spectral triple, not…

Operator Algebras · Mathematics 2019-10-03 Fedor Sukochev , Dmitriy Zanin

Spectral triples over noncommutative principal $\T^n$-bundles are studied, extending recent results about the noncommutative geometry of principal U(1)-bundles. We relate the noncommutative geometry of the total space of the bundle with the…

Quantum Algebra · Mathematics 2013-08-23 Alessandro Zucca , Ludwik Dabrowski

The spectral eta function for certain families of Dirac operators on noncommutative $3$-torus is considered and the regularity at zero is proved. By using variational techniques, we show that $\eta_{D}(0)$ is a conformal invariant. By…

Quantum Algebra · Mathematics 2015-04-07 Ali Fathi , Masoud Khalkhali

The scalar curvature for the noncommutative four torus $\mathbb{T}_\Theta^4$, where its flat geometry is conformally perturbed by a Weyl factor, is computed by making the use of a noncommutative residue that involves integration over the…

Quantum Algebra · Mathematics 2014-11-03 Farzad Fathizadeh

The curvature of the noncommutative torus $T^2_\theta$ ($\theta$ irrational) endowed with a noncommutative conformal metric has been the focus of attention of several recent works. Continuing the approach taken in the paper [A. Connes and…

Quantum Algebra · Mathematics 2017-03-10 Matthias Lesch , Henri Moscovici

An early result of Noncommutative Geometry was Connes' observation in the 1980's that the Dirac-Dolbeault cycle for the $2$-torus $\mathbb{T}^2$, which induces a Poincar\'e self-duality for $\mathbb{T}^2$, can be 'quantized' to give a…

K-Theory and Homology · Mathematics 2021-06-22 Anna Duwenig , Heath Emerson

In this paper we show that the value at zero of the zeta function of the Laplacian on the non-commutative two torus, endowed with its canonical conformal structure, is independent of the choice of the volume element (Weyl factor) given by a…

Quantum Algebra · Mathematics 2009-10-02 Alain Connes , Paula Tretkoff

We show the non-positivity of the Einstein-Hilbert action for conformal flat Riemannian metrics. The action vanishes only when the metric is constant flat. This recovers an earlier result of Fathizadeh-Khalkhali in the setting of spectral…

Differential Geometry · Mathematics 2018-07-19 Javad Golipour

We make some observations about Rosenberg's Levi-Civita connections on noncommutative tori, noting the non-uniqueness of torsion-free metric-compatible connections without prescribed connection operator for the inner *-derivations, the…

Operator Algebras · Mathematics 2018-01-11 Mira A. Peterka , Albert J. L. Sheu

The methods of spectral geometry are useful for investigating the metric aspects of noncommutative geometry and in these contexts require extensive use of pseudo-differential operators. In a foundational paper, Connes showed that, by direct…

Operator Algebras · Mathematics 2018-03-14 Jim Tao

We construct a new gauge theory on a pair of d-dimensional noncommutative tori. The latter comes from an intimate relationship between the noncommutative geometry associated with a lattice vertex operator algebra A and the noncommutative…

High Energy Physics - Theory · Physics 2009-10-31 G. Landi , F. Lizzi , R. J. Szabo

A general question behind this paper is to explore a good notion for intrinsic curvature in the framework of noncommutative geometry started by Alain Connes in the 80s. It has only recently begun (2014) to be comprehended via the intensive…

Operator Algebras · Mathematics 2016-06-28 Yang Liu
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