most recent 30 from http://mathoverflow.net 2013-05-23T20:23:57Z http://mathoverflow.net/feeds/question/109094 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/109094/ultrapowers-of-banach-algebras Albert harold 2012-10-07T19:33:12Z 2012-10-07T20:17:28Z

<p>Let $A$ ba a Banach algebra and $u$ be an arbitrary free ultrafilter. Let $A^{\bullet}$ be the unitization of $A$. Can we have <code>$((A)_{u})^{\bullet} = (A^{\bullet})_{u}$</code>?</p>