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UID:DSC-13818
DTSTART;TZID=Europe/Berlin:20171207T131500
SEQUENCE:1511966992
TRANSP:OPAQUE
DTEND;TZID=Europe/Berlin:20171207T141500
URL:https://www.dresden-science-calendar.de/calendar/de/detail/13818
LOCATION:TUD Willers-Bau\, Zellescher Weg 12-1401069 Dresden
SUMMARY:Fritz: On the decidability of noncommutative sums of squares\, with
  applications to Connes' embedding problem and quantum logic
CLASS:PUBLIC
DESCRIPTION:Speaker: Tobias Fritz \nInstitute of Speaker: MPI-MIS\, Leipzig
 \nTopics:\nMathematik\n Location:\n  Name: TUD Willers-Bau (WIL C 133)\n  
 Street: Zellescher Weg 12-14\n  City: 01069 Dresden\n  Phone: \n  Fax: \nD
 escription: Due to Positivstellensätze\, sums of squares play a fundament
 al  role in real algebraic geometry. While this remains true in the  nonco
 mmutative case\, the noncommutativity makes the problem generally  undecid
 able: there is no algorithm to decide whether a given  noncommutative poly
 nomial can be approximated by sums of squares. I will  explain why this is
  the case\, how it implies the undecidability of  quantum logic\, and how 
 it relates to Connes' embedding problem. Based on  arXiv:1207.0975 and arX
 iv:1607.05870.  
DTSTAMP:20261019T175331Z
CREATED:20171129T142956Z
LAST-MODIFIED:20171129T144952Z
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