Tomasz R. Taylor

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We show that certain type II string amplitudes at genus g are given by the topological partition function Fg discussed recently by Bershadsky, Cecotti, Ooguri and Vafa. These amplitudes give rise to a term in the four-dimensional effective action of the form ∑ g FgW 2g, where W is the chiral superfield of N = 2 supergravitational multiplet. The holomorphic(More)
We consider Type IIB orientifold models on Calabi-Yau spaces with three-form G-flux turned on. These fluxes freeze some of the complex structure moduli and the complex dilaton via an F-term scalar potential. By introducing pairs of D9-D9 branes with abelian magnetic fluxes it is possible to freeze also some of the Kähler moduli via a D-term potential.(More)
We test the recently conjectured duality between N=2 supersymmetric type II and heterotic string models by analysing a class of higher dimensional interactions in the respective low-energy Lagrangians. These are F -terms of the form FgW 2g where W is the gravitational superfield. On the type II side these terms are generated at the g-loop level and in fact(More)
We study quantum effects in five dimensions in heterotic superstring theory compactified on K3 × S1 and analyze the conjecture that its dual effective theory is eleven-dimensional supergravity compactified on a Calabi-Yau threefold. This theory is also equivalent to type II superstring theory compactified on the same Calabi-Yau manifold, in an appropriate(More)
We discuss the prepotential describing the effective field theory of N=2 heterotic superstring models. At the one loop-level the prepotential develops logarithmic singularities due to the appearance of charged massless states at particular surfaces in the moduli space of vector multiplets. These singularities modify the classical duality symmetry group(More)
We discuss supersymmetric Ward identities relating various scattering amplitudes in type I open superstring theory. We show that at the disk level, the form of such relations remains exactly the same, to all orders in α′, as in the low–energy effective field theory describing the α′ → 0 limit. This result holds in D = 4 for all compactifications, even for(More)
We consider scattering processes involving N gluonic massless states of open superstrings with a certain Regge slope alpha'. At the semiclassical level, the string world-sheet sweeps a disk and N gluons are created or annihilated at the boundary. We present exact expressions for the corresponding amplitudes, valid to all orders in alpha', for the so-called(More)
We extend the study of scattering amplitudes presented in “The LHC String Hunter’s Companion” [1] to the case of five-point processes that may reveal the signals of low mass strings at the LHC and are potentially useful for detailed investigations of fundamental Regge excitations. In particular, we compute the full–fledged string disk amplitudes describing(More)