https://en.formulasearchengine.com/w/api.php?action=feedcontributions&feedformat=atom&user=128.97.89.120formulasearchengine - User contributions [en]2026-08-19T03:17:06ZUser contributionsMediaWiki 1.47.0-wmf.7https://en.formulasearchengine.com/w/index.php?title=Stoner%E2%80%93Wohlfarth_model&diff=25982Stoner–Wohlfarth model2013-11-20T05:40:11Z<p>128.97.89.120: </p>
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<div>In [[group theory]], a branch of mathematics, a '''string group''' is an infinite-dimensional group String(''n'') introduced by {{harvtxt|Stolz|1996}} as a 3-connected cover of a spin group. <br />
A '''string manifold''' is a manifold with a lifting of its frame bundle to a string group bundle. <br />
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There is a short exact sequence of topological groups<br />
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:<math>0\rightarrow K(Z,2)\rightarrow \text{String}(n)\rightarrow \text{Spin}(n)\rightarrow 0</math><br />
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where ''K''('''Z''',&nbsp;2) is an [[Eilenberg&ndash;MacLane space]] and Spin(''n'') is a [[spin group]].<br />
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==References==<br />
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*{{Citation | last1=Henriques | first1=André G. | last2=Douglas | first2=Christopher L. | last3=Hill | first3=Michael A. | title=Homological obstructions to string orientations | url=http://arxiv.org/abs/0810.2131 | year=2008}}<br />
*{{Citation | last1=Wockel | first1=Christoph | last2=Sachse | first2=Christoph | last3=Nikolaus | first3=Thomas | title=A Smooth Model for the String Group | url=http://arxiv.org/abs/1104.4288 | year=2011}}<br />
*{{Citation | last1=Stolz | first1=Stephan | title=A conjecture concerning positive Ricci curvature and the Witten genus | doi=10.1007/BF01446319 | mr=1380455 | year=1996 | journal=[[Mathematische Annalen]] | issn=0025-5831 | volume=304 | issue=4 | pages=785–800}}<br />
*{{Citation | last1=Stolz | first1=Stephan | last2=Teichner | first2=Peter | title=Topology, geometry and quantum field theory | publisher=[[Cambridge University Press]] | series=London Math. Soc. Lecture Note Ser. | doi=10.1017/CBO9780511526398.013 | mr=2079378 | year=2004 | volume=308 | chapter=What is an elliptic object? | pages=247–343}}<br />
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==External links==<br />
*{{citation|first=J.|last=Baez|authorlink=John Baez|title=Higher Gauge Theory and the String Group|url=http://math.ucr.edu/home/baez/esi/|year=2007 }}<br />
*{{nlab|id=string+group|title=string group}}<br />
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[[Category:Group theory]]</div>128.97.89.120