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    <title>MaplePrimes - comments on Post, What is padic?</title>
    <link>http://www.mapleprimes.com/posts/125644-What-Is-Padic</link>
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    <description>The latest comments added to the Post, What is padic?</description>
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      <title>MaplePrimes - comments on Post, What is padic?</title>
      <link>http://www.mapleprimes.com/posts/125644-What-Is-Padic</link>
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    <item>
      <title>number theory</title>
      <link>http://www.mapleprimes.com/posts/125644-What-Is-Padic?ref=Feed:MaplePrimes:What is padic?:Comments#comment125681</link>
      <itunes:summary>&lt;p&gt;Number Theory&lt;br&gt;&lt;br&gt;It is decades ago, so a vague answer. And please do not take it as one to&lt;br&gt;look sooo much educated, it is just since nobody else takes the question.&lt;br&gt;&lt;br&gt;The guys in Number Theory use it in arithmetics Geometry, making heavy use&lt;br&gt;of cohomology theories (plural) in translating problems. One should find&lt;br&gt;more around "Weil Conjecture" on Wikipedia. Or Serre's book on Falting's&lt;br&gt;proof (in the bookshelf, section "I should ... but later or never ...").&lt;br&gt;&lt;br&gt;Never made up my mind to 'learn' it seriously, it is a tough machine ...&lt;/p&gt;
&lt;p&gt;Being ignorant I hesitate to say more.&lt;/p&gt;</itunes:summary>
      <description>The latest comments added to the Post, What is padic?</description>
      <guid>125681</guid>
      <pubDate>Thu, 15 Sep 2011 23:45:31 Z</pubDate>
      <itunes:author>Axel Vogt</itunes:author>
      <author>Axel Vogt</author>
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    <item>
      <title>p-adics</title>
      <link>http://www.mapleprimes.com/posts/125644-What-Is-Padic?ref=Feed:MaplePrimes:What is padic?:Comments#comment126355</link>
      <itunes:summary>&lt;p&gt;Not being a number theorist, I haven't made much use of p-adics.&amp;nbsp; However, the p-adic order of a rational number is something that is often quite handy, and padic[ordp] will compute it.&amp;nbsp; Thus if &lt;em&gt;p&lt;/em&gt; is a prime and&amp;nbsp; &lt;em&gt;r&lt;/em&gt; is a nonzero rational number,&lt;strong&gt; padic[ordp](r, p)&lt;/strong&gt; will compute the integer &lt;em&gt;n&lt;/em&gt; such that &lt;em&gt;r &lt;/em&gt;= &lt;em&gt;p&lt;sup&gt;n&lt;/sup&gt;a/b &lt;/em&gt;where &lt;em&gt;a&lt;/em&gt; and &lt;em&gt;b&lt;/em&gt; are integers coprime to &lt;em&gt;p&lt;/em&gt;.&lt;/p&gt;
&lt;p&gt;Another command in the &lt;strong&gt;padic&lt;/strong&gt; package is &lt;strong&gt;rootp&lt;/strong&gt;, which finds p-adic roots of a polynomial in one variable.&amp;nbsp; How might this be helpful to a non-specialist?&amp;nbsp; Well, it can be thought of as encoding information about the solutions of this polynomial modulo different powers of &lt;em&gt;p&lt;/em&gt;.&amp;nbsp; For example:&lt;/p&gt;
&lt;p&gt;&amp;gt; padic[rootp](x^3+x+3,13);&lt;/p&gt;
&lt;p&gt;&lt;img src="data:image/png;base64,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" alt=""&gt;&lt;/p&gt;
&lt;p&gt;So &lt;em&gt;x&lt;/em&gt;=9 is a solution of &lt;em&gt;x&lt;/em&gt;&lt;sup&gt;3&lt;/sup&gt;+&lt;em&gt;x&lt;/em&gt;+3 = 0 mod 13, and &lt;em&gt;x=&lt;/em&gt;9 + 6 . 13 = 87 is a solution of this equation mod 13&lt;sup&gt;2&lt;/sup&gt;, etc.: since (if rootp can be believed) there is a 13-adic root of the polynomial. the truncations of that root give solutions mod 13&lt;sup&gt;n&lt;/sup&gt; for each positive integer &lt;em&gt;n&lt;/em&gt;.&amp;nbsp; There happens to be another solution of &lt;em&gt;x&lt;/em&gt;&lt;sup&gt;3&lt;/sup&gt;+&lt;em&gt;x&lt;/em&gt;+3 = 0 mod 13, namely &lt;em&gt;x&lt;/em&gt; = 2, but that one doesn't "lift" to the next power of 13.&lt;/p&gt;</itunes:summary>
      <description>The latest comments added to the Post, What is padic?</description>
      <guid>126355</guid>
      <pubDate>Sat, 08 Oct 2011 03:18:53 Z</pubDate>
      <itunes:author>Robert Israel</itunes:author>
      <author>Robert Israel</author>
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    <item>
      <title>Applications</title>
      <link>http://www.mapleprimes.com/posts/125644-What-Is-Padic?ref=Feed:MaplePrimes:What is padic?:Comments#comment129132</link>
      <itunes:summary>&lt;p&gt;The&amp;nbsp; applications of p-adic numbers outside of&amp;nbsp; number theory and&amp;nbsp; algebra are discussed here: &lt;a href="http://mathoverflow.net/questions/84320/important-applications-of-p-adic-numbers-outside-of-algebra-and-number-theory"&gt;http://mathoverflow.net/questions/84320/important-applications-of-p-adic-numbers-outside-of-algebra-and-number-theory&lt;/a&gt;&lt;/p&gt;</itunes:summary>
      <description>The latest comments added to the Post, What is padic?</description>
      <guid>129132</guid>
      <pubDate>Tue, 27 Dec 2011 10:46:29 Z</pubDate>
      <itunes:author>Markiyan Hirnyk</itunes:author>
      <author>Markiyan Hirnyk</author>
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    <item>
      <title>What is the p-adic Mandelbroit set?</title>
      <link>http://www.mapleprimes.com/posts/125644-What-Is-Padic?ref=Feed:MaplePrimes:What is padic?:Comments#comment151041</link>
      <itunes:summary>&lt;p&gt;I would like to pay attention to &amp;nbsp;the recent notice &lt;a href="http://www.ams.org/notices/201308/rnoti-p1048.pdf"&gt;http://www.ams.org/notices/201308/rnoti-p1048.pdf&lt;/a&gt; .&lt;/p&gt;</itunes:summary>
      <description>The latest comments added to the Post, What is padic?</description>
      <guid>151041</guid>
      <pubDate>Wed, 28 Aug 2013 16:53:33 Z</pubDate>
      <itunes:author>Markiyan Hirnyk</itunes:author>
      <author>Markiyan Hirnyk</author>
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