We consider C/ZN and C/ZN orbifolds of heterotic string theories and ZN orbifolds of AdS3. We study theories with N=2 worldsheet superconformal invariance and construct RG flows. Following Harvey, Kutasov, Martinec and Moore, we compute gcl and show that it decreases monotonically along RG flowsas conjectured by them. For the heterotic string theories, the gauge degrees of freedom do not contri...

We show how the level matching condition in six dimensional, abelian and supersymmetric orbifolds of the E8 × E8 heterotic string can be given equivalently in terms of fractional gauge and gravitational instanton numbers. This relation is used to restate the classification of the orbifolds in terms of flat bundles away from the orbifold singularities under the constraint of the level matching c...

Sorghum breeding programs are based predominantly on developing homozygous lines to produce single cross hybrids, frequently with relatively narrow genetic bases. The adoption of complementary strategies, such as diversity study, enables a broader vision the structure germplasm. purpose this study was evaluate sorghum using analysis, principal components (PC) and clustering analyses. A total 16...

We present an overview of Gromov-Witten theory and its links with string theory compactifications, focussing on the GW potential as the generating function for topological string amplitudes at genus g. Restricting to CalabiYau target spaces, we give a complete derivation of the GW potential, discuss problems of multicovers and the infinite product expression. We explain the link with counting i...

We investigate the perturbative and non-perturbative correspondence of a class of four dimensional dual string constructions with N = 4 and N = 2 supersymmetry, obtained as Z2 or Z2 × Z2 orbifolds of the type II, heterotic and type I string. In particular, we discuss the heterotic and type I dual of all the symmetric Z2 × Z2 orbifolds of the type II string, classified in Ref. [1]. † Research su...

We show that the effective coupling constants τ of supersymmetric gauge theories described by hyperelliptic curves do not distinguish between the lattices of the two kinds of heterotic string. In particular, the following relation ΘD+ 16 (τ) = Θ2E8(τ) holds. This is reminiscent of the relation, by T -duality, of the two heterotic strings. We suggest that such a relation extends to all curves de...

This paper gives a detailed review of the work done by Hořava and Witten , who proposed that the strongly coupled limit of the E8 ×E8 heterotic string on R10 is the same as the low energy limit of M theory on R10 × S/Z2. This equivalence is then used to derive Heterotic-Type I duality from an eleven dimensional perspective. Lastly, applications of Hořava-Witten theory to phenomenology and cosmo...

We study a standard-embedding N = 2 heterotic string compactification on K3 × T 2 with a Wilson line turned on and perform a world-sheet calculation of string threshold correction. The result can be expressed in terms of the quantities appearing in the twoloop calculation of bosonic string. We also comment and speculate on the relevance of our result to generalized Kac-Moody superalgebra and N ...