BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20251122T001847EST-5103EnXH28@132.216.98.100 DTSTAMP:20251122T051847Z DESCRIPTION:Shanks sequence transformations and the $\varepsilon$-algorithm s. Theory and applications.\n\nWhen a sequence of numbers is slowly conver ging and when it is impossible to have access to the process producing it\ , it can be transformed\, by a {it sequence transformation}\, into a new s equence which\, under some assumptions\, converges faster to the same limi t. Among these general techniques is Shanks' transformation (Shanks\, 1949 \, 1955) which is arguably the best all-purpose method for accelerating co nvergence of sequences. First\, this transformation will be explained. The n\, we will see how it can be recursively implemented by the $arepsilon$-a lgorithm of Wynn (1956). This algorithm can be transformed to treat sequen ces of vectors (Wynn\, 1962). But\, since its algebraic theory is quite co mplicated\, another way to extend Shanks transformation to sequences of el ements of a general vector space $E$ was proposed (C.B.\, 1975). This topo logical Shanks transformation can be recursively implemented by the topolo gical $arepsilon$-algorithm. The rules of this algorithm are quite complic ated and difficult to implement since elements of E*\, the algebraic dual space of E\, recursively intervene in them. Recently\, these rules were gr eatly simplified\, thus leading to the simplified topological $arepsilon$- algorithm (C.B.\, M.R.-Z.\, 2014). First\, we will show how its recursive rule was derived from the old rules. Then\, this new algorithm and its imp lementation will be discussed. We will see the simplification it brought i n terms of arithmetical operations and storage. This algorithm will then b e applied to the solution of systems of linear and nonlinear vector and ma trix equations\, the computation of matrix functions\, and the solution of Fredholm integral equations of the second kind (C.B.\, M.R.-Z.\, 2017). T hese results were obtained by the freely available corresponding software (C.B.\, M.R.-Z.\, 2017). Travail conjoint avec Michela Redivo-Zaglia\, Uni versità di Padova\, Italia. Les transparents de la présentation seront en anglais\; la conférence sera donnée en anglais ou en français\, selon l'au dience.\n DTSTART:20171010T193000Z DTEND:20171010T203000Z LOCATION:Room 4336\, CA\, QC\, Montreal\, Pav. André-Aisenstadt\, 2920\, ch . de la Tour SUMMARY:Claude Brezinski\, Université de Lille - Sciences et Techniques\, F rance URL:/mathstat/channels/event/claude-brezinski-universi te-de-lille-sciences-et-techniques-france-272979 END:VEVENT END:VCALENDAR