An infinite dimensional umbral calculus Dmitri Finkelshtein Department of Mathematics, Swansea University, Singleton Park, Swansea SA2 8PP, U.K.; e-mail:
[email protected] Yuri Kondratiev Fakult¨atf¨urMathematik, Universit¨atBielefeld, 33615 Bielefeld, Germany; e-mail:
[email protected] Eugene Lytvynov Department of Mathematics, Swansea University, Singleton Park, Swansea SA2 8PP, U.K.; e-mail:
[email protected] Maria Jo~aoOliveira Departamento de Ci^enciase Tecnologia, Universidade Aberta, 1269-001 Lisbon, Por- tugal; CMAF-CIO, University of Lisbon, 1749-016 Lisbon, Portugal; e-mail:
[email protected] Abstract The aim of this paper is to develop foundations of umbral calculus on the space D0 of distri- d 0 butions on R , which leads to a general theory of Sheffer polynomial sequences on D . We define a sequence of monic polynomials on D0, a polynomial sequence of binomial type, and a Sheffer sequence. We present equivalent conditions for a sequence of monic polynomials on D0 to be of binomial type or a Sheffer sequence, respectively. We also construct a lift- ing of a sequence of monic polynomials on R of binomial type to a polynomial sequence of 0 0 binomial type on D , and a lifting of a Sheffer sequence on R to a Sheffer sequence on D . Examples of lifted polynomial sequences include the falling and rising factorials on D0, Abel, Hermite, Charlier, and Laguerre polynomials on D0. Some of these polynomials have already appeared in different branches of infinite dimensional (stochastic) analysis and played there a fundamental role. arXiv:1701.04326v2 [math.FA] 5 Mar 2018 Keywords: Generating function; polynomial sequence on D0; polynomial sequence of binomial type on D0; Sheffer sequence on D0; shift-invariance; umbral calculus on D0.