Stringy instanton corrections to $ \mathcal{N} = 2 $ gauge couplings (original) (raw)

Stringy instanton corrections to N=2 gauge couplings

2010

We discuss a string model where a conformal four-dimensional N=2 gauge theory receives corrections to its gauge kinetic functions from "stringy" instantons. These contributions are explicitly evaluated by exploiting the localization properties of the integral over the stringy instanton moduli space. The model we consider corresponds to a setup with D7/D3-branes in type I' theory compactified on T4/Z2 x T2, and possesses a perturbatively computable heterotic dual. In the heteoric side the corrections to the quadratic gauge couplings are provided by a 1-loop threshold computation and, under the duality map, match precisely the first few stringy instanton effects in the type I' setup. This agreement represents a very non-trivial test of our approach to the exotic instanton calculus.

Stringy instantons and dualities

Fortschritte der Physik, 2011

We discuss non-perturbative corrections to the gauge kinetic functions in a four-dimensional N = 2 gauge theory realized with a system of D7/D3-branes in a compactification of type I ′ theory on T4/Z2 × Z2. The non-perturbative contributions arise when D(-1) branes, corresponding to stringy instantons, are added to the system; such contributions can be explicitly evaluated using localization techniques and precisely match the results predicted by the heterotic/type I ′ duality. This agreement represents a very non-trivial test of the stringy multi-instanton calculus.

Fortschritte der Physik Stringy instantons and dualities

2016

Stringy instanton effects in N= 2 gauge theories

Arxiv preprint arXiv:1012.1122, 2010

Abstract: We study the non-perturbative effects induced by stringy instantons on N= 2 SU}(N) gauge theories in four dimensions, realized on fractional D3 branes in a C^ 3/Z_3 orientifold. The stringy instantons, corresponding to D (-1) branes that occupy a node of the orientifold ...

On the perturbative corrections around D-string instantons

Journal of High Energy Physics, 1999

We study F 4-threshold corrections in an eight dimensional S-dual pair of string theories, as a prototype of dual string vacua with sixteen supercharges. We show that the orbifold CFT description of D-string instantons gives rise to a perturbative expansion similar to the one appearing on the fundamental string side. By an explicit calculation, using the Nambu-Goto action in the static gauge, we show that the first subleading term agrees precisely on the two sides. We then give a general argument to show that the agreement extends to all orders.

Heterotic/type-I duality in D < 10 dimensions, threshold corrections and D-instantons

Journal of High Energy Physics, 1997

We continue our study of heterotic/type-I duality in D < 10 dimensions. We consider the heterotic and type-I theories compactified on tori to lower dimensions. We calculate the special ("BPS-saturated") F 4 and R 4 terms in the effective one-loop heterotic action. These terms are expected to be non-perturbatively exact for D > 4.

N = 2 Instanton Calculus in Closed String Background

Progress of Theoretical Physics Supplement, 2007

In this contribution we describe how to obtain instanton effects in four dimensional gauge theories by computing string scattering amplitudes in D3/D(-1) brane systems. In particular we study a system of fractional D3/D(-1) branes in a Z2 orbifold and in a Ramond-Ramond closed string background, and show that it describes the gauge instantons of N = 2 super Yang-Mills theory and their interactions with the graviphoton of N = 2. Using string theory methods we compute the prepotential of the effective gauge theory exploiting the localization methods of the instanton calculus, showing that this leads to the same information given by the topological string. * )

Classical gauge instantons from open strings

Journal of High Energy Physics, 2003

We study the D3/D(−1) brane system and show how to compute instanton corrections to correlation functions of gauge theories in four dimensions using open string techniques. In particular we show that the disks with mixed boundary conditions that are typical of the D3/D(−1) system are the sources for the classical instanton solution. This can then be recovered from simple calculations of open string scattering amplitudes in the presence of D-instantons. Exploiting this fact we also relate this stringy description to the standard instanton calculus of field theory.

Gauge instantons from open strings

Fortschritte der Physik, 2004

In this contribution we describe how to obtain instanton effects in four dimensional gauge theories by computing string scattering amplitudes in D3/D(−1) brane systems. In particular we show that the disks with mixed boundary conditions, which are typical of the D3/D(−1) system, are the sources for the classical instanton solution.

Three instanton computations in gauge theory and string theory

2005

We employ a variety of ideas from geometry and topology to perform three new instanton computations in gauge theory and string theory. First, we consider supersymmetric QCD with gauge group SU (N c) and with N f flavors. In this theory, it is well known that instantons generate a superpotential if N f = N c − 1 I would first and foremost like to thank my advisor, Edward Witten, for generously sharing his ideas and his time with me and, in particular, for suggesting the projects that form the basis of this thesis. It has been a great opportunity for me to work with Edward, from whom I have learned much, and this thesis is based entirely on our joint work. I would also like to thank especially my undergraduate advisor, Ronen Plesser, who first taught me about field theory, string theory, and (most importantly) what it means to conduct research. My work with Ronen, along with his constant encouragement, were

Stringy instanton corrections to $ \mathcal{N} = 2 $ gauge couplings (original) (raw)

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