Superpartient ratio: Difference between revisions

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<h2>IMPORTED REVISION FROM WIKISPACES</h2>
#REDIRECT [[Delta-N ratio]]
This is an imported revision from Wikispaces. The revision metadata is included below for reference:<br>
: This revision was by author [[User:guest|guest]] and made on <tt>2012-09-07 15:06:03 UTC</tt>.<br>
: The original revision id was <tt>362905360</tt>.<br>
: The revision comment was: <tt></tt><br>
The revision contents are below, presented both in the original Wikispaces Wikitext format, and in HTML exactly as Wikispaces rendered it.<br>
<h4>Original Wikitext content:</h4>
<div style="width:100%; max-height:400pt; overflow:auto; background-color:#f8f9fa; border: 1px solid #eaecf0; padding:0em"><pre style="margin:0px;border:none;background:none;word-wrap:break-word;white-space: pre-wrap ! important" class="old-revision-html">**Superpartient** numbers are ratios of the form p/q, where p and q are relatively prime (so that the fraction is reduced to lowest terms), and p - q is greater than 1. In ancient Greece they were called epimeric (epimerēs) ratios, which is literally translated as "above a part." In ancient Greece, fractions like 3/1 and 7/1 were not considered to be epimeric ratios because of their additional restriction that [[Harmonic|multiples of the fundamental]] cannot be epimeric. Epimeric ratios were considered to be inferior to epimoric ratios.


All epimeric ratios can be constructed as products of [[superparticular|superparticular numbers]]. This is due to the following useful identity:
[[Category:Terms]]
[[math]]
[[Category:Ancient Greek music]]
\prod_{i=1}^{P-1}\frac{i+1}{i}=P
[[math]]
 
When considering ratios, and particularly when they are ratios for [[comma|commas]], it can be useful to introduce the notion of the **degree of epimericity**. In terms of p/q reduced to lowest terms it is p - q. An epimoric ratio has degree 1, the 7-limit comma 245/243 degree 2, the 5-limit comma 128/125 degree 3, and so forth. [[http://en.wikipedia.org/wiki/St%C3%B8rmer's_theorem|Størmer's theorem]] can be extended to the claim that for each prime limit p and each degree of epimoricity n, there are only finitely many p-limit ratios with degree of epimoricity less than or equal to n.
 
See Also: [[ABC, High Quality Commas, and Epimericity]]</pre></div>
<h4>Original HTML content:</h4>
<div style="width:100%; max-height:400pt; overflow:auto; background-color:#f8f9fa; border: 1px solid #eaecf0; padding:0em"><pre style="margin:0px;border:none;background:none;word-wrap:break-word;width:200%;white-space: pre-wrap ! important" class="old-revision-html">&lt;html&gt;&lt;head&gt;&lt;title&gt;Superpartient&lt;/title&gt;&lt;/head&gt;&lt;body&gt;&lt;strong&gt;Superpartient&lt;/strong&gt; numbers are ratios of the form p/q, where p and q are relatively prime (so that the fraction is reduced to lowest terms), and p - q is greater than 1. In ancient Greece they were called epimeric (epimerēs) ratios, which is literally translated as &amp;quot;above a part.&amp;quot; In ancient Greece, fractions like 3/1 and 7/1 were not considered to be epimeric ratios because of their additional restriction that &lt;a class="wiki_link" href="/Harmonic"&gt;multiples of the fundamental&lt;/a&gt; cannot be epimeric. Epimeric ratios were considered to be inferior to epimoric ratios.&lt;br /&gt;
&lt;br /&gt;
All epimeric ratios can be constructed as products of &lt;a class="wiki_link" href="/superparticular"&gt;superparticular numbers&lt;/a&gt;. This is due to the following useful identity:&lt;br /&gt;
&lt;!-- ws:start:WikiTextMathRule:0:
[[math]]&amp;lt;br/&amp;gt;
\prod_{i=1}^{P-1}\frac{i+1}{i}=P&amp;lt;br/&amp;gt;[[math]]
--&gt;&lt;script type="math/tex"&gt;\prod_{i=1}^{P-1}\frac{i+1}{i}=P&lt;/script&gt;&lt;!-- ws:end:WikiTextMathRule:0 --&gt;&lt;br /&gt;
&lt;br /&gt;
When considering ratios, and particularly when they are ratios for &lt;a class="wiki_link" href="/comma"&gt;commas&lt;/a&gt;, it can be useful to introduce the notion of the &lt;strong&gt;degree of epimericity&lt;/strong&gt;. In terms of p/q reduced to lowest terms it is p - q. An epimoric ratio has degree 1, the 7-limit comma 245/243 degree 2, the 5-limit comma 128/125 degree 3, and so forth. &lt;a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/St%C3%B8rmer's_theorem" rel="nofollow"&gt;Størmer's theorem&lt;/a&gt; can be extended to the claim that for each prime limit p and each degree of epimoricity n, there are only finitely many p-limit ratios with degree of epimoricity less than or equal to n.&lt;br /&gt;
&lt;br /&gt;
See Also: &lt;a class="wiki_link" href="/ABC%2C%20High%20Quality%20Commas%2C%20and%20Epimericity"&gt;ABC, High Quality Commas, and Epimericity&lt;/a&gt;&lt;/body&gt;&lt;/html&gt;</pre></div>

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