منابع مشابه
Heterotic versus Type I
I compare the (prototype) calculations of special F 4 and R terms in the effective actions of the Spin(32)/Z2 heterotic and type I string theories, compactified on S and T . Besides checking duality, this elucidates the quantitative rules of D-brane calculus. I explain in particular (a) why D-branes do not run in loops, and (b) how their instanton contributions arise from orbifold fixed points ...
متن کاملEvidence for Heterotic - Type I String Duality
A study is made of the implications of heterotic string T -duality and extended gauge symmetry for the conjectured equivalence of heterotic and Type I superstrings. While at first sight heterotic string world-sheet dynamics appears to conflict with Type I perturbation theory, a closer look shows that Type I perturbation theory “miraculously” breaks down, in some cases via novel mechanisms, when...
متن کاملType IIB Orientifolds, F-theory, Type I Strings on Orbifolds and Type I - Heterotic Duality
We consider six and four dimensional N = 1 supersymmetric orientifolds of Type IIB compactified on orbifolds. We give the conditions under which the perturbative world-sheet orientifold approach is adequate, and list the four dimensional N = 1 orientifolds (which are rather constrained) that satisfy these conditions. We argue that in most cases orientifolds contain non-perturbative sectors that...
متن کاملHeterotic and Type I String Dynamics from Eleven Dimensions
We propose that the ten-dimensional E8 × E8 heterotic string is related to an elevendimensional theory on the orbifold R × S/Z2 in the same way that the Type IIA string in ten dimensions is related to R × S. This in particular determines the strong coupling behavior of the ten-dimensional E8 × E8 theory. It also leads to a plausible scenario whereby duality between SO(32) heterotic and Type I s...
متن کاملHeterotic / Type-i Duality and D-brane Instantons
We study heterotic/type I duality in d = 8, 9 uncompactified dimensions. We consider the special (“BPS saturated”) F4 and R4 terms in the effective one-loop heterotic action, which are expected to be non-perturbatively exact. Under the standard duality map these translate to tree-level, perturbative and non-perturbative contributions on the type I side. We check agreement with the one-loop open...
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ژورنال
عنوان ژورنال: Nuclear Physics B - Proceedings Supplements
سال: 1998
ISSN: 0920-5632
DOI: 10.1016/s0920-5632(98)00169-8