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	<title>Physics:(−1)F - Revision history</title>
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	<updated>2026-05-15T16:44:37Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
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		<title>WikiHarold: change</title>
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		<updated>2023-06-26T00:53:40Z</updated>

		<summary type="html">&lt;p&gt;change&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;{{Short description|Term in quantum field theory}}&lt;br /&gt;
{{DISPLAYTITLE:(−1)&amp;lt;sup&amp;gt;&amp;#039;&amp;#039;F&amp;#039;&amp;#039;&amp;lt;/sup&amp;gt;}}&lt;br /&gt;
{{Quantum mechanics}}&lt;br /&gt;
In a [[Physics:Quantum field theory|quantum field theory]] with [[Physics:Fermion|fermion]]s, &amp;#039;&amp;#039;&amp;#039;(−1)&amp;lt;sup&amp;gt;&amp;#039;&amp;#039;F&amp;#039;&amp;#039;&amp;lt;/sup&amp;gt;&amp;#039;&amp;#039;&amp;#039; is a [[Unitary operator|unitary]], Hermitian, [[Involution (mathematics)|involutive]] [[Operator (mathematics)|operator]] where &amp;#039;&amp;#039;F&amp;#039;&amp;#039; is the [[Physics:Fermion|fermion]] number operator. For the example of particles in the [[Physics:Standard Model|Standard Model]], it is equal to the sum of the lepton number plus the baryon number, {{nowrap|1=&amp;#039;&amp;#039;F&amp;#039;&amp;#039; = &amp;#039;&amp;#039;B&amp;#039;&amp;#039; + &amp;#039;&amp;#039;L&amp;#039;&amp;#039;}}.  The action of this operator is to multiply [[Physics:Boson|boson]]ic states by 1 and [[Physics:Fermion|fermion]]ic states by −1. This is always a global internal symmetry of any quantum field theory with fermions and corresponds to a rotation by 2π. This splits the [[Hilbert space]] into two superselection sectors. Bosonic operators commute with (−1)&amp;lt;sup&amp;gt;&amp;#039;&amp;#039;F&amp;#039;&amp;#039;&amp;lt;/sup&amp;gt; whereas fermionic operators anticommute with it.&amp;lt;ref name=&amp;quot;terning&amp;quot;&amp;gt;{{cite book | last = Terning | first = John| title = Modern Supersymmetry:Dynamics and Duality: Dynamics and Duality | publisher = [[Organization:Oxford University Press|Oxford University Press]] | date = 2006 | location = New York | url = https://books.google.com/books?id=1JMf-fcnOHYC&amp;amp;q=fermion+%22%28-1%29F%22&amp;amp;pg=PA5 | isbn = 0-19-856763-4}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
This operator really shows its utility in [[Physics:Supersymmetry|supersymmetric]] theories.&amp;lt;ref name=&amp;quot;terning&amp;quot;/&amp;gt; [[Physics:Witten index|Its trace]] is the [[Spectral asymmetry|spectral asymmetry]] of the fermion spectrum, and can be understood physically as the [[Physics:Casimir effect|Casimir effect]].&lt;br /&gt;
&lt;br /&gt;
==See also==&lt;br /&gt;
*[[Physics:Parity|Parity]]&lt;br /&gt;
*[[Physics:Primon gas|Primon gas]]&lt;br /&gt;
*Möbius function&lt;br /&gt;
&lt;br /&gt;
==References==&lt;br /&gt;
&amp;lt;references/&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Further reading==&lt;br /&gt;
* {{cite book | last = Shifman | first = Mikhail A. |  title = Advanced Topics in Quantum Field Theory: A Lecture Course | publisher = Cambridge University Press | date = 2012 | location = Cambridge | url = https://books.google.com/books?id=zeQuWycXV3oC&amp;amp;q=fermion+%22%28-1%29F%22&amp;amp;pg=PA581 | isbn = 978-0-521-19084-8}}&lt;br /&gt;
* {{cite book | last1 = Ibáñez | first1 = Luis E. | first2 = Angel M. | last2 = Uranga | title = String Theory and Particle Physics: An Introduction to String Phenomenology | publisher = Cambridge University Press | date = 2012 | location = Cambridge | url = https://books.google.com/books?id=vAUUu6DpVkUC&amp;amp;q=fermion+%22%28-1%29F%22&amp;amp;pg=PA111 | isbn = 978-0-521-51752-2}}&lt;br /&gt;
* {{cite book | last = Bastianelli | first = Fiorenzo | title = Path Integrals and Anomalies in Curved Space | publisher = Cambridge University Press | date = 2006 | location = Cambridge | url = https://books.google.com/books?id=HxpBObJ8roEC&amp;amp;q=%22%28-1%29F%22&amp;amp;pg=PA278 | isbn = 978-0-521-84761-2}}&lt;br /&gt;
&lt;br /&gt;
{{DEFAULTSORT:-1F}}&lt;br /&gt;
[[Category:Quantum field theory]]&lt;br /&gt;
[[Category:Supersymmetric quantum field theory]]&lt;br /&gt;
&lt;br /&gt;
{{Sourceattribution|(−1)F}}&lt;/div&gt;</summary>
		<author><name>WikiHarold</name></author>
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