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Related papers: Connes' calculus for The Quantum double suspension

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We investigate the regularity condition for twisted spectral triples. This condition is equivalent to the existence of an appropriate pseudodifferential calculus compatible with the spectral triple. A natural approach to obtain such a…

Operator Algebras · Mathematics 2020-09-17 Marco Matassa , Robert Yuncken

We find several new estimates for the spectral constants $K(\mathbb A_r)$ for which a closed annulus $\overline{\mathbb A}_r$ or closed polyannulus $\overline{\mathbb A}^n_r$ is a $K$-spectral set for operators in the quantum annulus…

Functional Analysis · Mathematics 2026-05-25 Sourav Pal , James E. Pascoe , Nitin Tomar

A non-classical differential calculus on the quantum disc and cones is constructed and the associated integral is calculated.

Quantum Algebra · Mathematics 2016-11-11 Tomasz Brzeziński , Ludwik Dąbrowski

In a very celebrated paper A. Connes has formulated a conjecture which is now one of the most important open problem in Operator Algebras. This importance comes from the works of many mathematicians who have found some unexpected equivalent…

Operator Algebras · Mathematics 2010-03-11 Valerio Capraro

We study the Connes spectral distance of quantum states and analyse the nonlocality of a 4D generalized noncommutative phase space. By virtue of the Hilbert-Schmidt operatorial formulation, we obtain the Dirac operator and construct a…

Mathematical Physics · Physics 2025-09-09 Bing-Sheng Lin , Tai-Hua Heng

The dual coalgebra of Podle\'s' quantum sphere O_q(S^2_c) is determined explicitly. This result is used to classify all finite dimensional covariant first order differential calculi over O_q(S^2_c) for all but exceptional values of the…

Quantum Algebra · Mathematics 2007-05-23 I. Heckenberger , S. Kolb

An algebraic analysis framework for quantum calculus is proposed. The quantum derivative operator $D_{\tau ,\sigma}$ is based on two commuting bijections $\tau$ and $\sigma$ defined on an arbitrary set $M$ equipped with a tension structure…

Quantum Algebra · Mathematics 2010-12-30 Piotr Multarzynski

We discuss a version of Pythagoras theorem in noncommutative geometry. Usual Pythagoras theorem can be formulated in terms of Connes' distance, between pure states, in the product of commutative spectral triples. We investigate the…

Mathematical Physics · Physics 2012-12-06 Francesco D'Andrea , Pierre Martinetti

For a unital C*-algebra A, which is equipped with a spectral triple and an extension T of A by the compacts, we construct a family of spectral triples associated to T and depending on the two positive parameters (s,t). Using Rieffel's…

Operator Algebras · Mathematics 2009-11-13 Erik Christensen , Cristina Ivan

We study the canonical quantization of the theory given by Chamseddine-Connes spectral action on a particular finite spectral triple with algebra $M_2(\Cset)\oplus\Cset$. We define a quantization of the natural distance associated with this…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Fabien Besnard

A semifinite spectral triple for an algebra canonically associated to canonical quantum gravity is constructed. The algebra is generated by based loops in a triangulation and its barycentric subdivisions. The underlying space can be seen as…

High Energy Physics - Theory · Physics 2009-04-08 Johannes Aastrup , Jesper M. Grimstrup , Ryszard Nest

We consider contractions of complexified real cones, as recently introduced by Rugh in [Rugh10]. Dubois [Dub09] gave optimal conditions to determine if a matrix contracts a canonical complex cone. First we generalize his results to the case…

Functional Analysis · Mathematics 2010-11-24 Loïc Dubois , Hans Henrik Rugh

We formulate a version of Baum-Connes' conjecture for a discrete quantum group, building on our earlier work (\cite{GK}). Given such a quantum group $\cla$, we construct a directed family $\{\cle_F \}$ of $C^*$-algebras ($F$ varying over…

K-Theory and Homology · Mathematics 2007-05-23 Debashish Goswami , A. O. Kuku

Continuing our study of spectral triples on quantum domains, we look at unbounded invariant and covariant derivations in the quantum annulus. In particular, we investigate whether such derivations can be implemented by operators with…

Operator Algebras · Mathematics 2018-03-06 Slawomir Klimek , Matt McBride , Sumedha Rathnayake

We show that the noncommutative differential geometry of quantum projective spaces is compatible with Rieffel's theory of compact quantum metric spaces. This amounts to a detailed investigation of the Connes metric coming from the unital…

Operator Algebras · Mathematics 2025-05-29 Max Holst Mikkelsen , Jens Kaad

The algebras obtained as fixed points of the action of the cyclic group $Z_N$ on the coordinate algebra of the quantum disc are studied. These can be understood as coordinate algebras of quantum or non-commutative cones. The following…

Quantum Algebra · Mathematics 2016-01-20 Tomasz Brzeziński

We give a proof of an analogue of Connes' Hochschild character theorem for twisted spectral triples obtained from twisting a spectral triple by scaling automorphisms, under some suitable conditions. We also survey some of the properties of…

Operator Algebras · Mathematics 2011-07-01 Farzad Fathizadeh , Masoud Khalkhali

This paper has two main objectives. The first one is to show that the Connes formulation of Dirac theory can be applied in the framework of quantum principal bundles for any n dimensional spectral triple, any quantum group, any quantum…

Quantum Algebra · Mathematics 2025-10-31 Gustavo Amilcar Saldaña Moncada

We study the noncommutative geometry of the Moyal plane from a metric point of view. Starting from a non compact spectral triple based on the Moyal deformation A of the algebra of Schwartz functions on R^2, we explicitly compute Connes'…

High Energy Physics - Theory · Physics 2011-07-20 Eric Cagnache , Francesco D'Andrea , Pierre Martinetti , Jean-Christophe Wallet

Our understanding of local index formula in noncommutative geometry is stalled for a while because we do not have more than one explicit computation, namely that of Connes for quantum SU(2) and do not understand the meaning of the various…

K-Theory and Homology · Mathematics 2017-08-02 Partha Sarathi Chakraborty , Bipul Saurabh