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| {{refimprove|date=October 2011}}
| | Hi there! :) My name is Kristopher, I'm a student studying Physical from Metz, France.<br><br>Review my page: [http://www.bbwconnections.com/index.php?do=/BarbraBorges/info/ 4inkjets promotion codes] |
| {{String theory}}
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| '''F-theory''' is a branch of [[string theory]] developed by [[Cumrun Vafa]].<ref>Cumrun Vafa. "Evidence for F-theory" [[arXiv]]: [http://arxiv.org/abs/hep-th/9602022 hep-th/9602022]</ref> The new [[vacua]] described as F-theory were discovered by Vafa, and {{cl-span|it|date=October 2012}} also allowed string theorists to construct new realistic vacua — in the form of F-theory [[compactification (physics)|compactified]] on elliptically fibered [[Calabi–Yau]] four-folds. The letter "F" supposedly stands for "Father".<ref>[http://www.youtube.com/watch?v=fW6JFKgbAF4&feature=relmfu Michio Kaku: The Universe Is a Symphony of Vibrating Strings - YouTube]</ref> | |
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| ==Compactifications==
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| F-theory is formally a 12-dimensional theory, but the only way to obtain an acceptable background is to [[Compactification (physics)|compactify]] this theory on a [[torus|two-torus]]. By doing so, one obtains [[type IIB string|type IIB]] [[superstring theory]] in 10 dimensions. The [[SL(2,Z)]] [[S-duality]] symmetry of the resulting type IIB string theory is manifest because it arises as the group of [[large diffeomorphism]]s of the two-dimensional [[torus]].
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| More generally, one can compactify F-theory on an elliptically fibered [[manifold]] ([[elliptic fibration]]), i.e. a [[fiber bundle]] whose fiber is a two-dimensional torus (also called an [[elliptic curve]]). For example, a subclass of the [[K3 manifold]]s is elliptically fibered, and F-theory on a K3 manifold is dual to [[heterotic string]] theory on a two-torus. (Eight dimensions are large.)
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| The well-known large number of semirealistic solutions to string theory referred to as the [[string theory landscape]], with <math>10^{500}</math> elements or so, is dominated by F-theory compactifications on [[Calabi–Yau four-fold]]s.
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| ==Phenomenology==
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| New models of [[Grand Unified Theory|unification of the fundamental forces]] have recently been developed using F-theory.<ref>[http://arxiv.org/abs/1001.0577 [1001.0577] Particle Physics Implications of F-theory]</ref>
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| ==Extra time dimensions==
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| F-theory, as it has [[metric signature]] (11,1), as needed for the Euclidean interpretation of the compactification spaces (e.g. the four-folds), is not a [[multiple time dimensions|"two-time" theory of physics]].
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| However, the signature of the two additional dimensions is somewhat ambiguous due to their infinitesimal character. For example, the [[supersymmetry]] of F-theory on a flat background corresponds to type IIB (i.e. (2,0)) supersymmetry with 32 real supercharges which may be interpreted as the dimensional reduction of the chiral real 12-dimensional supersymmetry if its spacetime signature is (10,2). In (11,1) dimensions, the minimum number of components would be 64.
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| == See also ==
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| * [[Dilaton]]
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| * [[Axion]]
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| ==References==
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| {{reflist}}
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| {{DEFAULTSORT:F-Theory}}
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| [[Category:String theory]]
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| {{string-theory-stub}}
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Hi there! :) My name is Kristopher, I'm a student studying Physical from Metz, France.
Review my page: 4inkjets promotion codes