Orbifolds by cyclic permutations in gepner type superstrings and in the corresponding Calabi-Yau manifolds

We show that string theory in AdS 3 has two distinct phases depending on the radius of curvature R AdS = √ kl s . For k > 1 (i.e. R AdS > l s ), the SL(2,C) invariant vacuum of the spacetime conformal field theory is normalizable, the high energy density of states is given by the Cardy formula with c eff = c, and generic high energy states look like large BTZ black holes. For k < 1, the SL(2,C) invariant vacuum as well as BTZ black holes are non-normalizable, c eff < c, and high energy states correspond to long strings that extend to the boundary of AdS 3 and become more and more weakly coupled there. A similar picture is found in asymptotically linear dilaton spacetime with dilaton gradient Q = 2 k . The entropy grows linearly with the energy in this case (for k > 1 2 ). The states responsible for this growth are two dimensional black holes for k > 1, and highly excited perturbative strings living in the linear dilaton throat for k < 1. The change of behavior at k = 1 in the two cases is an example of a string/black hole transition. The entropies of black holes and strings coincide at k = 1. 3/05

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“…This is precisely the type of expression one finds in the w-twisted sector of a symmetric orbifold, whose building block has c = 6k [26,27,25].…”

Section: Adsmentioning

confidence: 71%

Phases of quantum gravity in and linear dilaton backgrounds

et al. 2005

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“…Following [92,93] I use the most convenient description of the field content of (k) in terms of a free boson ϕ and the parafermion model at level k found in [88,94]:…”

Section: Jhep03(2006)102mentioning

confidence: 99%

A family of SCFTs hosting all ``very attractive'' relatives of the (2)⁴Gepner model

Wendland

2006

J. High Energy Phys.

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This work gives a manual for constructing superconformal field theories associated to a family of smooth K3 surfaces. A direct method is not known, but a combination of orbifold techniques with a non-classical duality turns out to yield such models. A four parameter family of superconformal field theories associated to certain quartic K3 surfaces in CP 3 is obtained, four of whose complex structure parameters give the parameters within superconformal field theory. Standard orbifold techniques are used to construct these models, so on the level of superconformal field theory they are already well understood.All "very attractive" K3 surfaces belong to the family of quartics underlying these theories, that is all quartic hypersurfaces in CP 3 with maximal Picard number whose defining polynomial is given by the sum of two polynomials in two variables. A particular member of the family is the (2) 4 Gepner model, such that these theories can be viewed as complex structure deformations of (2) 4 in its geometric interpretation on the Fermat quartic.

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“…Twisted scalar fields [1,2] and twisted vertex operators [3,4] were introduced in 1971 and 1975 respectively, although their role in string theory was not fully understood until the theory of orbifolds [5,6,7,8,9,10,11,12] was developed in the mid 1980's.…”

Section: Introductionmentioning

confidence: 99%

“…Some subalgebras of these orbifold algebras appear earlier in Refs. [13,12,14], and the role of these subalgebras in cyclic orbifolds was emphasized by Fuchs, Klemm and Schmidt [12]. With the help of the orbifold algebras, we find that all the familiar constructions of conformal field theory have their counterparts in the orbifolds, including affine-Sugawara constructions [15,16,17,18], coset constructions [15,16,19,20] and affine-Virasoro constructions [21,22,23], as well as SL(2,R)-Ward identities [24] and null-state differential equations of BPZ type.…”

Section: Introductionmentioning

confidence: 99%