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Related papers: Curved noncommutative torus and Gauss--Bonnet

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We describe noncommutative geometric aspects of twisted deformations, in particular of the spheres in Connes and Landi [8] and in Connes and Dubois Violette [7], by using the differential and integral calculus on these spaces that is…

Quantum Algebra · Mathematics 2007-05-23 Paolo Aschieri , Francesco Bonechi

The field equations of noncommutative gravity can be obtained by replacing all exterior products by twist-deformed exterior products in the action functional of general relativity, and are here studied by requiring that the torsion 2-form…

High Energy Physics - Theory · Physics 2015-06-18 Elisabetta Di Grezia , Giampiero Esposito , Patrizia Vitale

It is shown that the local axial anomaly in $2-$dimensions emerges naturally if one postulates an underlying noncommutative fuzzy structure of spacetime . In particular the Dirac-Ginsparg-Wilson relation on ${\bf S}^2_F$ is shown to contain…

High Energy Physics - Theory · Physics 2014-11-18 Badis Ydri

We first propose a conformal geometry for Connes-Landi noncommutative manifolds and study the associated scalar curvature. The new scalar curvature contains its Riemannian counterpart as the commutative limit. Similar to the results on…

Quantum Algebra · Mathematics 2018-03-14 Yang Liu

It is pointed out that the usual $\theta$-algebra assumed for non-commuting coordinates is not $P$- and $T$-invariant, unless one {\it formally} transforms the non-commutativity parameter $\theta^{\mu\nu}$ in an appropriate way. On the…

High Energy Physics - Theory · Physics 2009-11-10 Katsusada Morita

Let $f$ be a regular non-constant symbol defined on the $d$-dimensional torus ${\mathbb T}^d$ with values on the unit circle. Denote respectively by $\kappa$ and $L$, its set of critical points and the associated Laurent operator on…

Functional Analysis · Mathematics 2015-02-02 M. A. Astaburuaga , O. Bourget , V. H. Cortés

We study $T\bar{T}$-deformed $O(N)$ scalar field theory in two-dimensional spacetime using the functional renormalization group. We derive the $\beta$ functions for the couplings in the system and explore the fixed points. In addition to…

High Energy Physics - Theory · Physics 2024-03-15 Jie Liu , Junichi Haruna , Masatoshi Yamada

We study the spectral functional tr f(D+A) for a suitable function f, a self-adjoint operator D having compact resolvent, and a certain class of bounded self-adjoint operators A. Such functionals were introduce by Chamseddine and Connes in…

Functional Analysis · Mathematics 2010-12-16 Walter D. van Suijlekom

In this paper we investigate the connection between (non-)geometry and (non-)commutativity of the closed string. To this end, we solve the classical string on three T-dual toroidal backgrounds: a torus with H-flux, a twisted torus and a…

High Energy Physics - Theory · Physics 2015-06-12 David Andriot , Magdalena Larfors , Dieter Lust , Peter Patalong

On complete non-compact manifolds with bounded sectional curvature, we consider a class of self-adjoint Dirac-type operators called Dirac-Schr\"odinger operators. Assuming two Dirac-Schr\"odinger operators coincide at infinity, by previous…

Differential Geometry · Mathematics 2026-04-14 Pengshuai Shi

We compare the eigenvalues of the Dirac and Laplace operator on a two-dimensional torus with respect to the trivial spin structure. In particular, we compute their variation up to order 4 upon deformation of the flat metric, study the…

Differential Geometry · Mathematics 2007-05-23 Ilka Agricola , Bernd Ammann , Thomas Friedrich

The model of dual superconductivity has been revisited considering the $U(1)$-gauged Ginzburg-Landau lagrangian density on a non-commutative torus $T^{2}_{NC}$, according to a new approach, we propose, in dealing with non-commutative space…

High Energy Physics - Theory · Physics 2018-05-01 Andrea Spirito

Using perturbative expansion in terms of powers of the rotation parameter $a$ we construct the axisymmetric and asymptotically flat black-hole metric in the $D$-dimensional Einstein-Gauss-Bonnet theory. In five-dimensional spacetime we find…

General Relativity and Quantum Cosmology · Physics 2020-10-15 R. A. Konoplya , A. Zhidenko

We formulate and prove an extension of Connes's reconstruction theorem for commutative spectral triples to so-called Connes-Landi or isospectral deformations of commutative spectral triples along the action of a compact Abelian Lie group…

Mathematical Physics · Physics 2026-01-15 Branimir Ćaćić

We investigate a set of functional equations defining a projection in the noncommutative 2-torus algebra $A_{\theta}$. The exact solutions of these provide various generalisations of the Powers-Rieffel projection. By identifying the…

K-Theory and Homology · Mathematics 2014-03-25 Michał Eckstein

We initiate the study of a q-deformed geometry for quantum SU(2). In contrast with the usual properties of a spectral triple, we get that only twisted commutators between algebra elements and our Dirac operator are bounded. Furthermore, the…

Quantum Algebra · Mathematics 2015-05-30 Jens Kaad , Roger Senior

As an application of the Bochner formula, we prove that if a $2$-dimensional Riemannian manifold admits a non-trivial smooth tangent vector field $X$ then its Gauss curvature is the divergence of a tangent vector field, constructed from…

Differential Geometry · Mathematics 2019-11-21 J. M. Almira , A. Romero

We show that the supermembrane theory compactified on a torus is invariant under T-duality. There are two different topological sectors of the compactified supermembrane (M2) classified according to a vanishing or nonvanishing second…

High Energy Physics - Theory · Physics 2016-11-23 M. P. Garcia del Moral , J. M. Pena , A. Restuccia

The irrelevant composite operator $T\bar{T}$, constructed from components of the stress-energy tensor, exhibits unique properties in two-dimensional quantum field theories and represents a distinctive form of integrable deformation.…

High Energy Physics - Theory · Physics 2025-01-22 Nicolò Brizio , Tommaso Morone , Roberto Tateo

In this paper we prove a version of Connes' trace theorem for noncommutative tori of any dimension~$n\geq 2$. This allows us to recover and improve earlier versions of this result in dimension $n=2$ and $n=4$ by Fathizadeh-Khalkhali. We…

Operator Algebras · Mathematics 2020-05-20 Raphael Ponge