972 research outputs found
D-branes on the Quintic
We study D-branes on the quintic CY by combining results from several
directions: general results on holomorphic curves and vector bundles, stringy
geometry and mirror symmetry, and the boundary states in Gepner models recently
constructed by Recknagel and Schomerus, to begin sketching a picture of
D-branes in the stringy regime. We also make first steps towards computing
superpotentials on the D-brane world-volumes.Comment: harvmac, 78 pp (v3: notes added and improved discussion of an
example
Deforming, revolving and resolving - New paths in the string theory landscape
In this paper we investigate the properties of series of vacua in the string
theory landscape. In particular, we study minima to the flux potential in type
IIB compactifications on the mirror quintic. Using geometric transitions, we
embed its one dimensional complex structure moduli space in that of another
Calabi-Yau with h^{1,1}=86 and h^{2,1}=2. We then show how to construct
infinite series of continuously connected minima to the mirror quintic
potential by moving into this larger moduli space, applying its monodromies,
and moving back. We provide an example of such series, and discuss their
implications for the string theory landscape.Comment: 41 pages, 5 figures; minor corrections, published versio
The elliptic genus from split flows and Donaldson-Thomas invariants
We analyze a mixed ensemble of low charge D4-D2-D0 brane states on the
quintic and show that these can be successfully enumerated using attractor flow
tree techniques and Donaldson-Thomas invariants. In this low charge regime one
needs to take into account worldsheet instanton corrections to the central
charges, which is accomplished by making use of mirror symmetry. All the
charges considered can be realized as fluxed D6-D2-D0 and anti-D6-D2-D0 pairs
which we enumerate using DT invariants. Our procedure uses the low charge
counterpart of the picture developed Denef and Moore. By establishing the
existence of flow trees numerically and refining the index factorization
scheme, we reproduce and improve some results obtained by Gaiotto, Strominger
and Yin. Our results provide appealing evidence that the strong split flow tree
conjecture holds and allows to compute exact results for an important sector of
the theory. Our refined scheme for computing indices might shed some light on
how to improve index computations for systems with larger charges.Comment: 37 pages, 12 figure
Metastable Quivers in String Compactifications
We propose a scenario for dynamical supersymmetry breaking in string
compactifications based on geometric engineering of quiver gauge theories. In
particular we show that the runaway behavior of fractional branes at del Pezzo
singularities can be stabilized by a flux superpotential in compact models. Our
construction relies on homological mirror symmetry for orientifolds.Comment: 22 pages, 1 figure; v2: references adde
Domain Wall Junctions in Supersymmetric Field Theories in D=4
We study the possible BPS domain wall junction configurations for general
polynomial superpotentials of N=1 supersymmetric Wess-Zumino models in D=4. We
scan the parameter space of the superpotential and find different possible BPS
states for different values of the deformation parameters and present our
results graphically. We comment on the domain walls in F/M/IIA theories
obtained from the Calabi-Yau fourfolds with isolated singularities and a
background flux.Comment: 26 pages, 4 figure
D-branes on some one- and two-parameter Calabi-Yau hypersurfaces
D-branes on one-parameter Calabi-Yau spaces and two-parameter K3-fibered
Calabi-Yau manifolds are analyzed from both the Gepner model point of view and
the geometric perspective. We compute part of the spectrum of the boundary
states and comment on the appearance of the D0-brane as well as on
nonsupersymmetric large volume configurations becoming supersymmetric at the
Gepner point.Comment: LaTeX2e, 23 pages. v2: typos corrected, references added, JHEP styl
Chirality Change in String Theory
It is known that string theory compactifications leading to low energy
effective theories with different chiral matter content ({\it e.g.} different
numbers of standard model generations) are connected through phase transitions,
described by non-trivial quantum fixed point theories.
We point out that such compactifications are also connected on a purely
classical level, through transitions that can be described using standard
effective field theory. We illustrate this with examples, including some in
which the transition proceeds entirely through supersymmetric configurations.Comment: 50 pages, 2 figure
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