#### Filter Results:

- Full text PDF available (11)

#### Publication Year

2001

2016

- This year (0)
- Last 5 years (2)
- Last 10 years (5)

#### Publication Type

#### Co-author

#### Journals and Conferences

Learn More

- Oleg Andreev, Tassilo Ott
- 2001

We compute the one-loop corrections to the tachyon potentials in both, bosonic and supersym-metric, cases by worldsheet methods. In fact, there is no contradiction between this approach and the Feynman diagram expansions arising from the tree level effective actions. In the process, we also get some insight on tachyon condensation from the viewpoint of… (More)

We analyze the perturbative stability of non-supersymmetric intersecting brane world models on tori. Besides the dilaton tadpole, a dynamical instability in the complex structure moduli space occurs at string disc level, which drives the background geometry to a degenerate limit. We show that in certain orbifold models this latter instability is absent as… (More)

We review the construction and phenomenology of intersecting brane worlds. The breaking of chiral and supersymmetry together with a reduction of gauge symmetry by introducing D-branes at generic angles into type I or type II string compactifications is taken as a starting point for the engineering of phenomenologically appealing four-dimensional vacua.… (More)

We study supersymmetric intersecting D6-branes wrapping 3-cycles in the Type IIA T 6 /Z Z 4 orientifold background. As a new feature, the 3-cycles in this orbifold space arise both from the untwisted and the Z Z 2 twisted sectors. We present an integral basis for the homology lattice, H 3 (M, Z Z), in terms of fractional 3-cycles, for which the intersection… (More)

- Tassilo Ott
- 2003

Intersecting branes have been the subject of an elaborate string model building for several years. After a general introduction into string theory, this work introduces in detail the toroidal and Z N-orientifolds. The picture involving D9-branes with B-fluxes is shortly reviewed, but the main discussion employs the T-dual picture of intersecting D6-branes.… (More)

Non-supersymmetric brane world scenarios in string theory display perturbative instabili-ties that usually involve runaway potentials for scalar moduli fields. We investigate in the framework of intersecting brane worlds whether the leading order scalar potential for the closed string moduli allows to satisfy the slow-rolling conditions required for… (More)

- Paul Koerber, J. Van Craen, +17 authors Stijn Nevens
- 2004

There is geometry in the humming of the strings. Acknowledgements The first words of thanks I extend to my thesis advisor, Alexander Sevrin, for five years of fruitful cooperation before and during the work on my Ph.D. thesis, for encouragement when the flood of string theory was overwhelming at times, for his contagious enthusiasm, fail-safe support and… (More)

- Tassilo Ott
- 2005

These lecture notes give a short introduction of the derivation of the super-symmetric standard model on the Z6-orientifold as published in hep-th/0404055. Untwisted and twisted cycles are constructed and one specific model is discussed in more detail.

- Gabriele Honecker, Tassilo Ott
- 2008

In this paper, globally N = 1 supersymmetric configurations of intersecting D6-branes on the Z 6 orientifold are discussed, involving also fractional branes. It turns out rather miraculously that one is led almost automatically to just one particular class of 5 stack models containing the SM gauge group, which all have the same chiral spectrum. The further… (More)

- H. Spielmann, B. Grune, +6 authors R. Ahl
- Bundesgesundheitsblatt
- 2009

Weltweit haben in den letzten 20 Jahren Wissenschaftler in Industrie und Behörden Tierversuche bei der Entwicklung und Zulassung neuer Arzneimittel kontinuierlich verringern können. Allein in Deutschland konnte die Zahl der Versuchstiere auf diesem Gebiet von 4,2 Millionen im Jahre 1977 auf 740 000 im Jahre 1996 verringert werden. Dazu haben gemeinsam die… (More)