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DTSTART:20220830T120000Z
DTEND:20220830T124500Z
SUMMARY:DCAMM seminar - Fractional power series and the method of dominant balances
DESCRIPTION:<p><span>A DCAMM seminar will be presented by</span></p>\n<p style="margin-bottom: 0.0001pt; text-align: center;"><strong><span><br />\nProfessor C.J. Chapman,<br />\nKeele University, United Kingdom<br />\n<br />\n</span></strong></p>\n<p style="margin-bottom: 0.0001pt; text-align: center;"><strong><span>\n&nbsp;<br />\n</span></strong></p>\n&nbsp;&nbsp;\n<p style="margin-top: 0cm; margin-right: 0cm; margin-bottom: 0.0001pt; text-align: justify;"><strong><span>Abstract:<br />\n<br />\n</span></strong><span style="text-align: left;">This talk describes a general treatment of the method of dominant balances for a</span><span style="text-align: left;">&nbsp; </span><span style="text-align: left;">polynomial equation, in which parameters are to be&nbsp;</span><span style="text-align: left;">scaled in such a way that the maximum possible number of terms in the equation is in balance at leading order.</span><span style="text-align: left;">&nbsp; </span><span style="text-align: left;">This leads in general&nbsp;</span><span style="text-align: left;">to a fractional power series (a `Puiseux series'), in which, surprisingly, there can be large and irregular gaps (lacunae) in the fractional&nbsp;</span><span style="text-align: left;">powers actually occurring. A complete theory is given to determine the gaps, requiring the notion of a Frobenius set from number&nbsp;</span><span style="text-align: left;">theory, and its complement, a Sylvester set. The talk is applied in outlook, as the method of dominant balances is widely used in physics&nbsp;</span><span style="text-align: left;">and engineering, where it gives results of extraordinary accuracy, far beyond the expected range.</span><span style="text-align: left;">&nbsp; </span><span style="text-align: left;">The work has been conducted in a collaboration begun at the Isaac Newton Institute, Cambridge, with H. P. Wynn (London School of Economics).</span><span style="text-align: left;">&nbsp; </span><span style="text-align: left;">We believe the results&nbsp;</span><span style="text-align: left;">are new.</span><span style="text-align: left;">&nbsp; </span><span style="text-align: left;">Despite hundreds of years of use of Puiseux series (since 1676), we are not aware of any previous attempt to give a complete quantitative account of their gaps.</span></p>\n<p style="text-align: justify;"><span style="color: black;">\n<br />\n</span><span style="color: black;">Danish pastry, coffee and tea will be served 15 minutes before the seminar starts.</span></p>\n<p><span style="text-align: justify;">&nbsp;All interested persons are invited</span></p>
X-ALT-DESC;FMTTYPE=text/html:<p><span>A DCAMM seminar will be presented by</span></p>\n<p style="margin-bottom: 0.0001pt; text-align: center;"><strong><span><br />\nProfessor C.J. Chapman,<br />\nKeele University, United Kingdom<br />\n<br />\n</span></strong></p>\n<p style="margin-bottom: 0.0001pt; text-align: center;"><strong><span>\n&nbsp;<br />\n</span></strong></p>\n&nbsp;&nbsp;\n<p style="margin-top: 0cm; margin-right: 0cm; margin-bottom: 0.0001pt; text-align: justify;"><strong><span>Abstract:<br />\n<br />\n</span></strong><span style="text-align: left;">This talk describes a general treatment of the method of dominant balances for a</span><span style="text-align: left;">&nbsp; </span><span style="text-align: left;">polynomial equation, in which parameters are to be&nbsp;</span><span style="text-align: left;">scaled in such a way that the maximum possible number of terms in the equation is in balance at leading order.</span><span style="text-align: left;">&nbsp; </span><span style="text-align: left;">This leads in general&nbsp;</span><span style="text-align: left;">to a fractional power series (a `Puiseux series'), in which, surprisingly, there can be large and irregular gaps (lacunae) in the fractional&nbsp;</span><span style="text-align: left;">powers actually occurring. A complete theory is given to determine the gaps, requiring the notion of a Frobenius set from number&nbsp;</span><span style="text-align: left;">theory, and its complement, a Sylvester set. The talk is applied in outlook, as the method of dominant balances is widely used in physics&nbsp;</span><span style="text-align: left;">and engineering, where it gives results of extraordinary accuracy, far beyond the expected range.</span><span style="text-align: left;">&nbsp; </span><span style="text-align: left;">The work has been conducted in a collaboration begun at the Isaac Newton Institute, Cambridge, with H. P. Wynn (London School of Economics).</span><span style="text-align: left;">&nbsp; </span><span style="text-align: left;">We believe the results&nbsp;</span><span style="text-align: left;">are new.</span><span style="text-align: left;">&nbsp; </span><span style="text-align: left;">Despite hundreds of years of use of Puiseux series (since 1676), we are not aware of any previous attempt to give a complete quantitative account of their gaps.</span></p>\n<p style="text-align: justify;"><span style="color: black;">\n<br />\n</span><span style="color: black;">Danish pastry, coffee and tea will be served 15 minutes before the seminar starts.</span></p>\n<p><span style="text-align: justify;">&nbsp;All interested persons are invited</span></p>

URL:http://www.dcamm.dk/da/Kalender/2022/08/Seminar_No_756
DTSTAMP:20260929T161000Z
UID:{7BC815CA-D02E-40B3-9469-F3B17C165AFC}-20220830T120000Z-20220830T120000Z
LOCATION: Auditorium B - 5.034, Aalborg University,, Dept. of Matematical Sciences, Skjernvej 4A
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