The factorial-basis method for finding definite-sum solutions of linear recurrences with polynomial coefficients

التفاصيل البيبلوغرافية
العنوان: The factorial-basis method for finding definite-sum solutions of linear recurrences with polynomial coefficients
المؤلفون: Jiménez-Pastor, Antonio, Petkovšek, Marko
المصدر: Journal of Symbolic Computation. 117:15-50
بيانات النشر: Elsevier BV, 2023.
سنة النشر: 2023
مصطلحات موضوعية: FOS: Computer and information sciences, Computer Science - Symbolic Computation, 33F10, 39A06, 68W30, Computational Mathematics, Algebra and Number Theory, Computer Science - Mathematical Software, Symbolic Computation (cs.SC), Mathematical Software (cs.MS)
الوصف: The problem of finding a nonzero solution of a linear recurrence $Ly = 0$ with polynomial coefficients where $y$ has the form of a definite hypergeometric sum, related to the Inverse Creative Telescoping Problem of [14][Sec. 8], has now been open for three decades. Here we present an algorithm (implemented in a SageMath package) which, given such a recurrence and a quasi-triangular, shift-compatible factorial basis $\mathcal{B} = \langle P_k(n)\rangle_{k=0}^\infty$ of the polynomial space $\mathbb{K}[n]$ over a field $\mathbb{K}$ of characteristic zero, computes a recurrence satisfied by the coefficient sequence $c = \langle c_k\rangle_{k=0}^\infty$ of the solution $y_n = \sum_{k=0}^\infty c_kP_k(n)$ (where, thanks to the quasi-triangularity of $\mathcal{B}$, the sum on the right terminates for each $n \in \mathbb{N}$). More generally, if $\mathcal{B}$ is $m$-sieved for some $m \in \mathbb{N}$, our algorithm computes a system of $m$ recurrences satisfied by the $m$-sections of the coefficient sequence $c$. If an explicit nonzero solution of this system can be found, we obtain an explicit nonzero solution of $Ly = 0$.
62 pages
تدمد: 0747-7171
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6c0e672c98838e755cdc0a31c2adc0e1
https://doi.org/10.1016/j.jsc.2022.11.002
حقوق: OPEN
رقم الأكسشن: edsair.doi.dedup.....6c0e672c98838e755cdc0a31c2adc0e1
قاعدة البيانات: OpenAIRE