<p>In this paper, we use noncommutative differential geometry to formalize a framework for discrete differential calculus. We begin with a brief review of inverse limit of posets as an approximation of topological spaces. We then show how to associate a <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(C^*\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>C</mi> <mo>∗</mo> </msup> </math></EquationSource> </InlineEquation>-algebra over a poset, giving it a piecewise-linear structure. Furthermore, we explain how dually the algebra of continuous function <i>C</i>(<i>M</i>) over a manifold <i>M</i> can be approximated by a direct limit of <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(C^*\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>C</mi> <mo>∗</mo> </msup> </math></EquationSource> </InlineEquation>-algebras over posets. Finally, in the spirit of noncommutative differential geometry, we define a finite dimensional spectral triple on each poset. We show how the usual finite difference calculus is recovered as the eigenvalues of the commutator with the Dirac operator. We prove a convergence result in the case of the <i>d</i>-lattice in <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\mathbb {R}^d\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mrow> <mi mathvariant="double-struck">R</mi> </mrow> <mi>d</mi> </msup> </math></EquationSource> </InlineEquation> and for the torus <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(\mathbb {T}^d\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mrow> <mi mathvariant="double-struck">T</mi> </mrow> <mi>d</mi> </msup> </math></EquationSource> </InlineEquation>.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Noncommutative differential geometry on infinitesimal spaces

  • Damien Tageddine,
  • Jean-Christophe Nave

摘要

In this paper, we use noncommutative differential geometry to formalize a framework for discrete differential calculus. We begin with a brief review of inverse limit of posets as an approximation of topological spaces. We then show how to associate a \(C^*\) C -algebra over a poset, giving it a piecewise-linear structure. Furthermore, we explain how dually the algebra of continuous function C(M) over a manifold M can be approximated by a direct limit of \(C^*\) C -algebras over posets. Finally, in the spirit of noncommutative differential geometry, we define a finite dimensional spectral triple on each poset. We show how the usual finite difference calculus is recovered as the eigenvalues of the commutator with the Dirac operator. We prove a convergence result in the case of the d-lattice in \(\mathbb {R}^d\) R d and for the torus \(\mathbb {T}^d\) T d .