diff --git a/books/bookvolbib.pamphlet b/books/bookvolbib.pamphlet index cdc7266..66d3083 100644 --- a/books/bookvolbib.pamphlet +++ b/books/bookvolbib.pamphlet @@ -6248,6 +6248,376 @@ Proc ISSAC 97 pp172-175 (1997) \end{chunk} +\section{Symbolic Summation} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +\index{Karr, Michael} +\begin{chunk}{axiom.bib} +@Article{Karr85, + author = "Karr, Michael", + title = "Theory of Summation in Finite Terms", + year = "1985", + journal = "Journal of Symbolic Computation", + volume = "1", + number = "3", + month = "September", + pages = "303-315", + paper = "Karr85.pdf", + abstract = " + This paper discusses some of the mathematical aspects of an algorithm + for finding formulas for finite sums. The results presented here + concern a property of difference fields which show that the algorithm + does not divide by zero, and an analogue to Liouville's theorem on + elementary integrals." +} + +\end{chunk} + +\index{Karr, Michael} +\begin{chunk}{axiom.bib} +@article{Karr81, + author = "Karr, Michael", + title = "Summation in Finite Terms", + journal = "Journal Association for Computing Machinery", + year = "1981", + volume = "28", + number = "2", + month = "April", + issn = "0004-5411", + pages = "305--350", + url = "http://doi.acm.org/10.1145/322248.322255", + publisher = "ACM", + paper = "Karr81", + abstract = " + Results which allow either the computation of symbolic solutions to + first-order linear difference equations or the determination that + solutions of a certain form do not exist are presented. Starting with + a field of constants, larger fields may be constructed by the formal + adjunction of symbols which behave like solutions to first-order + linear equations (with a few restrictions). It is in these extension + fields that the difference equations may be posed and in which the + solutions are requested. The principal application of these results is + in finding formulas for a broad class of finite sums or in showing the + nonexistence of such formula." +} + +\end{chunk} + +\index{Zima, Eugene V.} +\begin{chunk}{axiom.bib} +@article{Zima13, + author = "Zima, Eugene V.", + title = "Accelerating Indefinite Summation: Simple Classes of Summands", + journal = "Mathematics in Computer Science", + year = "2013", + month = "December", + volume = "7", + number = "4", + pages = "455--472", + paper = "Zima13.pdf", + abstract = " + We present the history of indefinite summation starting with classics + (Newton, Montmort, Taylor, Stirling, Euler, Boole, Jordan) followed by + modern classics (Abramov, Gosper, Karr) to the current implementation + in computer algebra system Maple. Along with historical presentation + we describe several ``acceleration techniques'' of algorithms for + indefinite summation which offer not only theoretical but also + practical improvements in running time. Implementations of these + algorithms in Maple are compared to standard Maple summation tools" +} + +\end{chunk} + +\index{Er\"ocal, Bur\c{c}in} +\begin{chunk}{axiom.bib} +@article{Eroc10, + author = {Er\"ocal, Bur\c{c}in}, + title = "Summation in Finite Terms Using Sage", + journal = "ACM Commun. Comput. Algebra", + volume = "44", + number = "3/4", + month = "January", + year = "2011", + issn = "1932-2240", + pages = "190--193", + url = "http://doi.acm.org/10.1145/1940475.1940517", + publisher = "ACM", + paper = "Eroc10.pdf", + abstract = " + The summation analogue of the Risch integration algorithm developed by + Karr uses towers of difference fields to model nested indefinite sums + and products, as the Risch algorithm uses towers of differential + fields to model the so called {\sl elementary functions}. The + algorithmic machinery developed by Karr, and later generalized and + extended, allows one to find solutions of first order difference + equations over such towers of difference fields, in turn simplifying + expressions involving sums and products. + + We present an implementation of this machinery in the open source + computer algebra system Sage. Due to the nature of open source + software, this allows direct experimentation with the algorithms and + structures involved while taking advantage of the state of the art + primitives provided by Sage. Even though these methods are used behind + the scenes in the summation package Sigma and they were previously + implemented, this is the first open source implementation." +} + +\end{chunk} + +\index{Er\"ocal, Bur\c{c}in} +\begin{chunk}{axiom.bib} +@phdthesis{Eroc11, + author = {Er\"ocal, Bur\c{c}in}, + title = "Algebraic Extensions for Symbolic Summation", + school = "RISC Research Institute for Symbolic Computation", + year = "2011", + url = + "http://www.risc.jku.at/publications/download/risc_4320/erocal_thesis.pdf", + paper = "Eroc11.pdf", + abstract = " + + The main result of this thesis is an effective method to extend Karr's + symbolic summation framework to algebraic extensions. These arise, for + example, when working with expressions involving $(-1)^n$. An + implementation of this method, including a modernised version of + Karr's algorithm is presented. + + Karr's algorithm is the summation analogue of the Risch algorithm for + indefinite integration. In the summation case, towers of specialized + difference fields called $\prod\sum$-fields are used to model nested + sums and products. This is similar to the way elementary functions + involving nested logarithms and exponentials are represented in + differential fields in the integration case. + + In contrast to the integration framework, only transcendental + extensions are allowed in Karr's construction. Algebraic extensions of + $\prod\sum$-fields can even be rings with zero divisors. Karr's + methods rely heavily on the ability to solve first-order linear + difference equations and they are no longer applicable over these + rings. + + Based on Bronstein's formulation of a method used by Singer for the + solution of differential equations over algebraic extensions, we + transform a first-order linear equation over an algebraic extension to + a system of first-order equations over a purely transcendental + extension field. However, this domain is not necessarily a + $\prod\sum$-field. Using a structure theorem by Singer and van der + Put, we reduce this system to a single first-order equation over a + $\prod\sum$-field, which can be solved by Karr's algorithm. We also + describe how to construct towers of difference ring extensions on an + algebraic extension, where the same reduction methods can be used. + + A common bottleneck for symbolic summation algorithms is the + computation of nullspaces of matrices over rational function + fields. We present a fast algorithm for matrices over $\mathbb{Q}(x)$ + which uses fast arithmetic at the hardware level with calls to BLAS + subroutines after modular reduction. This part is joint work with Arne + Storjohann." +} + +\end{chunk} + +\index{Schneider, Carsten} +\begin{chunk}{axiom.bib} +@article{Schn05, + author = "Schneider, Carsten", + title = "A new Sigma approach to multi-summation", + year = "2005", + journal = "Advances in Applied Mathematics", + volume = "34", + number = "4", + pages = "740--767", + paper = "Schn05.pdf", + abstract = " + We present a general algorithmic framework that allows not only to + deal with summation problems over summands being rational expressions + in indefinite nested syms and products (Karr, 1981), but also over + $\delta$-finite and holonomic summand expressions that are given by a + linear recurrence. This approach implies new computer algebra tools + implemented in Sigma to solve multi-summation problems efficiently. + For instacne, the extended Sigma package has been applied successively + to provide a computer-assisted proof of Stembridge's TSPP Theorem." +\end{chunk} + +\index{Kauers, Manuel} +\begin{chunk}{axiom.bib} +@article{Kaue07, + author = "Kauers, Manuel", + title = "Summation algorithms for Stirling number identities", + year = "2007", + journal = "Journal of Symbolic Computation", + volume = "42", + number = "10", + month = "October", + pages = "948--970", + paper = "Kaue07.pdf", + abstract = " + We consider a class of sequences defined by triangular recurrence + equations. This class contains Stirling numbers and Eulerian numbers + of both kinds, and hypergeometric multiples of those. We give a + sufficient criterion for sums over such sequences to obey a recurrence + equation, and present algorithms for computing such recurrence + equations efficiently. Our algorithms can be used for verifying many + known summation identities on Stirling numbers instantly, and also for + discovering new identities." +} + +\end{chunk} + +\index{Schneider, Carsten} +\index{Kauers, Manuel} +\begin{chunk}{axiom.bib} +@article{Kaue08, + author = "Kauers, Manuel and Schneider, Carsten", + title = "Indefinite summation with unspecified summands", + year = "2006", + journal = "Discrete Mathematics", + volume = "306", + number = "17", + pages = "2073--2083", + paper = "Kaue80.pdf", + abstract = " + We provide a new algorithm for indefinite nested summation which is + applicable to summands involving unspecified sequences $x(n)$. More + than that, we show how to extend Karr's algorithm to a general + summation framework by which additional types of summand expressions + can be handled. Our treatment of unspecified sequences can be seen as + a first illustrative application of this approach." +} + +\end{chunk} + +\index{Schneider, Carsten} +\begin{chunk}{axiom.bib} +@article{Schn08, + author = "Schneider, Carsten", + title = "A refined difference field theory for symbolic summation", + year = "2008", + journal = "Journal of Symbolic Computation", + volume = "43", + number = "9", + pages = "611--644", + paper = "Schn08.pdf", + abstract = " + In this article we present a refined summation theory based on Karr's + difference field approach. The resulting algorithms find sum + representations with optimal nested depth. For instance, the + algorithms have been applied successively to evaluate Feynman + integrals from Perturbative Quantum Field Theory" +} + +\end{chunk} + +\index{Schneider, Carsten} +\begin{chunk}{axiom.bib} +@article{Schn09, + author = "Schneider, Carsten", + title = "Structural theorems for symbolic summation", + journal = "Proc. AAECC-2010", + year = "2010", + volume = "21", + pages = "1--32", + paper = "Schn09.pdf", + abstract = " + Starting with Karr's structural theorem for summation - the discrete + version of Liouville's structural theorem for integration - we work + out crucial properties of the underlying difference fields. This leads + to new and constructive structural theorems for symbolic summation. + E.g., these results can be applied for harmonic sums which arise + frequently in particle physics." +} + +\end{chunk} + +\index{Schneider, Carsten} +\begin{chunk}{axiom.bib} +@phdthesis{Schn01, + author = "Schneider, Carsten", + title = "Symbolic Summation in Difference Fields", + school = "RISC Research Institute for Symbolic Computation", + year = "2001", + url = + "http://www.risc.jku.at/publications/download/risc_3017/SymbSumTHESIS.pdf", + paper = "Schn01.pdf", + abstract = " + + There are implementations of the celebrated Gosper algorithm (1978) on + almost any computer algebra platform. Within my PhD thesis work I + implemented Karr's Summation Algorithm (1981) based on difference + field theory in the Mathematica system. Karr's algorithm is, in a + sense, the summation counterpart of Risch's algorithm for indefinite + integration. Besides Karr's algorithm which allows us to find closed + forms for a big clas of multisums, we developed new extensions to + handle also definite summation problems. More precisely we are able to + apply creative telescoping in a very general difference field setting + and are capable of solving linear recurrences in its context. + + Besides this we find significant new insights in symbolic summation by + rephrasing the summation problems in the general difference field + setting. In particular, we designed algorithms for finding appropriate + difference field extensions to solve problems in symbolic summation. + For instance we deal with the problem to find all nested sum + extensions which provide us with additional solutions for a given + linear recurrence of any order. Furthermore we find appropriate sum + extensions, if they exist, to simplify nested sums to simpler nested + sum expressions. Moreover we are able to interpret creative + telescoping as a special case of sum extensions in an indefinite + summation problem. In particular we are able to determine sum + extensions, in case of existence, to reduce the order of a recurrence + for a definite summation problem." + +} + +\end{chunk} + +\index{Schneider, Carsten} +\begin{chunk}{axiom.bib} +@InProceedings{Schn07, + author = "Schneider, Carsten", + title = "Symbolic Summation Assists Combinatorics", + year = "2007", + booktitle = "S\'eminaire Lotharingien de Combinatoire", + volume = "56", + article = "B56b", + url = "", + paper = "Schn07.pdf", + abstract = " + We present symbolic summation tools in the context of difference + fields that help scientists in practical problem solving. Throughout + this article we present multi-sum examples which are related to + combinatorial problems." +} + +\end{chunk} + +\index{Schneider, Carsten} +\begin{chunk}{axiom.bib} +@InProceedings{Schn00, + author = "Schneider, Carsten", + title = "An implementation of Karr's summation algorithm in Mathematica", + year = "2000", + booktitle = "S\'eminaire Lotharingien de Combinatoire", + volume = "S43b", + pages = "1-10", + url = "", + paper = "Schn00.pdf", + abstract = " + Implementations of the celebrated Gosper algorithm (1978) for + indefinite summation are available on almost any computer algebra + platform. We report here about an implementation of an algorithm by + Karr, the most general indefinite summation algorithm known. Karr's + algorithm is, in a sense, the summation counterpart of Risch's + algorithm for indefinite integration. This is the first implementation + of this algorithm in a major computer algebra system. Our version + contains new extensions to handle also definite summation problems. In + addition we provide a feature to find automatically appropriate + difference field extensions in which a closed form for the summation + problem exists. These new aspects are illustrated by a variety of + examples." + +} + +\end{chunk} + \section{To Be Classified} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \index{Kaltofen, Erich} diff --git a/changelog b/changelog index f498757..3af7c95 100644 --- a/changelog +++ b/changelog @@ -1,3 +1,5 @@ +20141008 tpd src/axiom-website/patches.html 20141008.03.tpd.patch +20141008 tpd books/bookvolbib add a section on Symbolic Summation 20141008 jtw src/axiom-website/patches.html 20141008.02.jtw.patch 20141008 jtw books/bookvolbib add Whee12 biblio reference 20141008 jtw books/bookvol10.1 add chapter on differential forms diff --git a/patch b/patch index cd6fcae..60bc62c 100644 --- a/patch +++ b/patch @@ -1,3 +1,3 @@ -books/bookvol10.1 add chapter on differential forms +books/bookvolbib add a section on Symbolic Summation -James Wheeler contributed documentation on differential forms +Collect references to papers on symbolic summation using Karr's method diff --git a/src/axiom-website/patches.html b/src/axiom-website/patches.html index 0a16fe8..c79b4ca 100644 --- a/src/axiom-website/patches.html +++ b/src/axiom-website/patches.html @@ -4676,6 +4676,8 @@ books/bookvol10.3 DERHAM: fix signature of 'degree'
books/bookvol10.3 DERHAM: add code for differential forms
20141008.02.jtw.patch books/bookvol10.1 add chapter on differential forms
+20141008.03.tpd.patch +books/bookvolbib add a section on Symbolic Summation