TH Institute on String Phenomenology

Contribution List

24. Welcome coffee

7/21/08, 11:00 AM

W1

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to welcome participants just arriving, and to discuss informally

1. J. Louis: "Compactifications on Generalized Geometries"

7/21/08, 2:00 PM

W1

I review compactifications on manifolds with SU(3) and SU(3)xSU(3) structure emphasising the structure of the low energy effective action.

6. A. Micu: "String dualities and manifolds with SU(3) structure"

7/21/08, 2:30 PM

W1

In this talk I will concentrate on the Heterotic - Type IIA duality when fluxes are turned on. I will show that in a specific case the duality involves M-theory rather than type IIA strings. For this case I will show the construction on the M-theory side which is dual to the heterotic compactifiactions on K3 x T^2 when gauge field fluxes along the torus are considered.

45. Discussion Coffee

7/21/08, 3:00 PM

W1

We meet in the discussion room after the seminars to continue discussion in an informal atmosphere.

28. Morning coffee

7/22/08, 11:00 AM

W1

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

2. K. Becker: "Torsional heterotic geometries"

7/22/08, 2:00 PM

W1

We construct some new examples of torsional heterotic backgrounds using duality with orientifold flux compactifications. We then explain how duality provides a solution to the heterotic string Bianchi identity which is an equation of Monge-Ampere type. Finally, we propose the existence of a much larger class of compact torsional geometries based on intuition from string duality.

3. P. G. Camara: "Torsion induced soft-breaking terms"

7/22/08, 2:30 PM

W1

We discuss the conditions for having no-scale solutions of type IIA and IIB supergravity compactified on orientifolds with SU(3) structure. Supersymmetry is spontaneusly broken at tree-level by the effect of the intrinsic torsion. The torsion induced mu-terms in the world-volume of D5, D6 and D9-branes are presented for the particular case of twisted-tori, and the arising patterns of...

46. Discussion Coffee

7/22/08, 3:00 PM

W1

We meet in the discussion room after the seminars to continue discussion in an informal atmosphere.

29. Morning coffee

7/23/08, 11:00 AM

W1

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

4. D. Lust: "The Landscape of String Theory: Intersecting branes (statistics and collider signatures) and AdS flux vacua

7/23/08, 2:00 PM

W1

It is known that the number of ground states is very big. This landscape of string vacua contains intersecting brane constructions as well as flux vacua. We will review some of the properties of intersecting branes, like their statistics and possible signatures at the LHC collider. At the end of the talk we are planning to discuss anti-de Sitter flux vacua and transitions between different...

47. Discussion Coffee

7/23/08, 3:00 PM

W1

The TH group meets in the discussion room after the colloquium to continue discussion in an informal atmosphere.

30. Morning coffee

7/24/08, 11:00 AM

W1

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

22. W. Taylor: "Cosmology and particle physics in the type IIA landscape"

7/24/08, 2:00 PM

W1

The apparently vast landscape of stable and metastable solutions to string theory raises the possibility that string theory may be able to reproduce virtually any reasonable low-energy theory. We describe one corner of the string landscape (IIA) where it seems that the range of possible cosmological models may be more constrained than particle physics.

23. G. Shiu: "UV Physics and String Inflation"

7/24/08, 2:30 PM

W1

Inflation has become the standard paradigm of early universe cosmology. Several outstanding questions in inflationary cosmology, however, require an understanding of the underlying UV physics. In this talk, I will discuss some of these issues and argue how one might turn these UV sensitivities into observational opportunities for string inflation.

48. Discussion Coffee

7/24/08, 3:00 PM

W1

We meet in the discussion room after the seminars to continue discussion in an informal atmosphere.

58. B. Acharya: "Non-thermal Dark Matter and Moduli/Gravitino Problems in M theory"

7/25/08, 10:00 AM

W1

TBA

57. M. Gomez-Reino: "dS vacua and modular inflation in N=1 supergravity and string theory"

7/25/08, 10:30 AM

W1

I will discuss the possibility of obtaining vacua with spontaneously broken supersymmetry and non-negative cosmological constant in the moduli sector of string models, as well as the possibility of realising slow-roll inflation. I will show that there exist some simple conditions for this to happen which depend only on the Kahler potential. I will then analyse the implications of these...

31. Morning coffee

7/25/08, 11:00 AM

W1

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

25. Welcome coffee

7/28/08, 11:00 AM

W2

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to welcome participants just arriving, and to discuss informally

7. R. Blumenhagen: "Instantons in N=1 string compactifications"

7/28/08, 2:00 PM

W2

In the first part an overview about recent developments on D-brane instantons effects in N=1 string compactifications is given. In the second part new effects based on so-called poly instantons are proposed.

9. E. Dudas: "Multi-instanton and one-loop string corrections in toroidal orbifold models

7/28/08, 2:30 PM

W2

We analyze N=2 perturbative and non-perturbative corrections in type I orbifold models where a dual heterotic description is available. We consider in particular the Bianchi-Sagnotti-Gimon-Polchinski orbifold. By exploiting perturbative calculations of the physical gauge couplings on the heterotic side, we obtain multi-instanton and one-loop string corrections to the K\"ahler potential and the...

50. Discussion Coffee

7/28/08, 3:00 PM

W2

We meet in the discussion room after the seminars to continue discussion in an informal atmosphere.

32. Morning coffee

7/29/08, 11:00 AM

W2

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

0. C. Vafa:"F-theory Meets Phenomenology"

7/29/08, 2:00 PM

W2

TBA

51. Discussion Coffee

7/29/08, 3:00 PM

W2

We meet in the discussion room after the seminars to continue discussion in an informal atmosphere.

10. A. Wingerter: "Orbifolds, the Standard Model, and Unification"

7/30/08, 10:00 AM

W2

We first highlight some of the (theoretical) shortcomings of the Standard Model, and then consider hints at physics beyond the electroweak scale. Grand Unification and theories in extra dimensions are motivated, and string orbifolds are introduced as ultraviolet completions of these theories. We present a general search strategy for MSSM-like models based on a local SO(10) Grand Unified...

44. M. Cvetic: "A string theoretic model of gauge mediated supersymmetry breaking"

7/30/08, 10:30 AM

W2

Guided by modern String Theory We propose a robust supergravity model of dynamical supersymmetry breaking and gauge mediation. The Polonyi field (and its mirror) is a chiral field, charged under ``anomalous'' U(1)'s, with hierarchical Polonyi-term which can be generated by string instantons, and quartic superpotential terms which arise naturally as a tree-level decoupling effect of massive...

33. Morning coffee

7/30/08, 11:00 AM

W2

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

61. R. Tatar: "New Aspects of Heterotic- F theory duality"

7/31/08, 10:00 AM

W2

The duality between the Heterotic and F-theory is a powerful tool in gaining more insights into F-theory description of low-energy chiral multiplets. Because chiral multiplets from bundles /\^2 V and /\^2 V^x as well as those from a bundle V are all involved in Yukawa couplings in Heterotic compactification, we need to translate descriptions of all those kinds of matter multiplets into...

60. M. Schulz: "String Junctions, Abelian Fibrations, and Flux/Geometry Duality"

7/31/08, 10:30 AM

W2

The simplest class of flux compactifications, type IIB toroidal orientifolds with N=2 flux, is dual to a class of purely geometric IIA Calabi-Yau compactifications with no flux. Since the duality relates warped and nonwarped compactifications, it has the potential to teach us how to define warped Kaluza-Klein reduction, for which we do not yet have a satisfactory definition. The duality...

34. Morning coffee

7/31/08, 11:00 AM

W2

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

62. V. Braun:"Heterotic Model Building"

8/1/08, 10:00 AM

W2

I will survey some aspects of geometric compactifications of heterotic strings and their low-energy phenomenology. In particular, I will focus on heterotic "non-standard embeddings". First, I will try to give a brief overview over the role of vector bundles in that construction, and how they can be constructed. Using our "heterotic standard model", I will discuss how the spectrum and...

64. K. Dienes: "A New Approach to Flavor?"

8/1/08, 10:30 AM

W2

The origin of flavor is one of the biggest mysteries of the Standard Model. Despite more than a half-century of data, we still have almost no explanation for family replication in the Standard Model. Many theoretical models can incorporate or accommodate this replication, but very few actually explain/predict/require it. In this talk, I will describe some recent work on a possible new...

35. Morning coffee

8/1/08, 11:00 AM

W2

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

26. Welcome coffee

8/4/08, 11:00 AM

W3

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to welcome participants just arriving, and to discuss informally

12. K. Choi: "Some features of soft terms in flux compactification"

8/4/08, 2:00 PM

W3

I discuss some features of soft SUSY breaking terms in flux compactification, which include flavor and CP conserving modulus mediation, sequestered uplifting, and the effect of anomalous U(1) symmetry.

13. H.-P. Nilles: "The Gaugino Code"

8/4/08, 2:30 PM

W3

Gauginos might play a crucial role in the search for supersymmetry at the Large Hadron Collider (LHC). Mass predictions for gauginos are rather robust and often related to the values of the gauge couplings. We analyse the ratios of gaugino masses in the LHC energy range for various string theories and various schemes of supersymmetry breakdown and mediation. Three distinct mass patterns emerge.

52. Discussion Coffee

8/4/08, 3:00 PM

W3

We meet in the discussion room after the seminars to continue discussion in an informal atmosphere.

36. Morning coffee

8/5/08, 11:00 AM

W3

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

14. B. Ovrut: "Ricci-Flat Metrics and Scalar Laplacians on Calabi-Yau Threefolds"

8/5/08, 2:00 PM

W3

A mathematical/numerical algrithm is presented for computing Ricci-flat metrics on Calabi-Yau threefolds. This will be explicitly applied to quintics, Z5XZ5 quotients of quintics as well as to the Z3XZ3 threefold of the Heterotic Standard Model. Using these metrics, a procedure is given for explictly calculating the eigenvalue/eigenfunction spectrum of the scalar Laplacian on these Calabi-Yau...

15. S. de Alwis: "Supersymmetry breaking models and String theory constraints"

8/5/08, 2:30 PM

W3

A consistent theory of supersymmetry breaking must have a hidden sector an observable sector and must be embedded in a locally supersymmetric theory which arises from string theory. For phenomenological reasons it must also transmit supersymmetry from the hidden to the visible sector in a dominantly flavor neutral manner. Also any such theory of supersymmetry breaking has to take into acount...

53. Discussion Coffee

8/5/08, 3:00 PM

W3

We meet in the discussion room after the seminars to continue discussion in an informal atmosphere.

16. A. Maharana: "Isometries and Approximate Flavor Symmetries in Local Models"

8/6/08, 10:00 AM

W3

We shall present a mechanism to generate flavor symmetries in local D-brane constructions. The key ingredient shall be approximate isometries of the local geometry. We shall discuss our findings in the context of general arguments for the absence of continuous global symmetries in string compactifications. Implications of the mechanism for the Large Volume Scenario for moduli stabilization...

17. P. Kumar: "Connecting the LHC with underlying theories"

8/6/08, 10:30 AM

W3

The talk will discuss some issues in trying to connect underlying theories with data at the LHC; in particular the challenges and the opportunities therein.

37. Morning coffee

8/6/08, 11:00 AM

W3

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

63. M. Trapletti: "Toric resolution of Heterotic orbifolds"

8/7/08, 10:00 AM

W3

We describe how to reproduce a large class of heterotic orbifold models as compactifications of 10d SUGRA on smooth manifolds in the presence of gauge fluxes. We show how to construct the smooth manifolds by resolving the orbifold singularity using toric geometry, and how to consistently embed U(1) gauge fluxes on them. Finally we match the obtained models with the standard heterotic orbifold models.

59. F. Gmeiner: "Millions of Standard Models on Z6'?"

8/7/08, 10:30 AM

W3

I discuss recent results obtained in collaboration with Gabriele Honecker (arXiv:0806.3039 [hep-th]) on a statistical analysis of standard model-like compactifications on the T^6/Z_6' orbifold in the context of intersecting brane models of type II string theory. In particular the structure of the hidden sector, the gauge coupling constants and chiral exotic matter content is discussed. It...

38. Morning coffee

8/7/08, 11:00 AM

W3

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

66. M. Bianchi: "D-branes on T-folds with few T's"

8/8/08, 10:00 AM

W3

Most of the mechanisms for moduli stabilization in String Theory involve R-R fluxes that can only be treated in the supergravity approximation. Non-geometric vacumm configurations with L-R asymmetric `T-duality' twists and shifts allow to stabilize closed string moduli in a controllable way. Peculiarities of bound-states of D-branes in these backgrounds will be discussed in view of...

67. P. Anastasopoulos: "Anomalous U(1)'s at LHC"

8/8/08, 10:30 AM

W3

I will study an extension of the MSSM by an anomalous abelian vector multiplet and a Stuckelberg multiplet. The anomalies are cancelled by the Green-Schwarz mechanism and the introduction of three-gauge-boson couplings that provide a massive boson like Z' with additional new couplings that have not been considered in the past. I will study the effects of these anomaly related terms and we show...

39. Morning coffee

8/8/08, 11:00 AM

W3

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

27. Welcome coffee

8/11/08, 11:00 AM

W4

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to welcome participants just arriving, and to discuss informally

18. G. Villadoro: "Status of D6-brane flux models and their effective field theories"

8/11/08, 2:00 PM

W4

19. S. Raby: "A Fertile Patch in the Heterotic Landscape"

8/11/08, 2:30 PM

W4

This talk is a follow-up to the talk of Akin Wingerter. I will focus on some of the phenomenological details of one benchmark model discussed in 0708.2691[hep-th].

54. Discussion Coffee

8/11/08, 3:00 PM

W4

We meet in the discussion room after the seminars to continue discussion in an informal atmosphere.

40. Morning coffee

8/12/08, 11:00 AM

W4

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

20. J. Gray: "Uses and methodology of the STRINGVACUA Mathematica package"

8/12/08, 2:00 PM

W4

I will discuss various applications of the subject of algorithmic algebraic geometry to string phenomenology. In particular i will demonstrate some of the functionality of the recently released STRINGVACUA mathematica package, which facilitates the use of such methods for physicists in our field. Examples will include the analysis of flux vacua and computing Yukawa couplings in smooth,...

21. B. Schellekens: "Topics in RCFT orientifolds"

8/12/08, 2:30 PM

W4

A large set of exact string spectra can be explored using orientifolds of rational conformal field theories. Several results will be discussed, including a variety of ways of realizing the standard model, distributions of physical quantities, free fermionic constructions, neutrino masses and non-supersymmetric, tachyon-free spectra.

55. Discussion Coffee

8/12/08, 3:00 PM

W4

We meet in the discussion room after the seminars to continue discussion in an informal atmosphere.

71. Discussion Session: "The String Landscape"

8/13/08, 10:00 AM

Discussion led by M. Douglas, B. Schellekens and H. Verlinde on the string theory landscape and its impact on particle physics and cosmology

41. Morning coffee

8/13/08, 11:00 AM

W4

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

5. M. Douglas: "Landscape, low energy supersymmetry, and warping"

8/13/08, 2:00 PM

W4

A very central question in phenomenology is, what mechanism solves the hierarchy problem. For a long time the only generally accepted solution was low energy supersymmetry. In recent years, other solutions inspired by string theory have been suggested, such as large extra dimensions and warping. Even more recently, the idea that string theory contains a large landscape of solutions,...

56. Discussion Coffee

8/13/08, 3:00 PM

W4

We meet in the discussion room after the seminars to continue discussion in an informal atmosphere.

68. J.F. Morales:"Non-perturbative interactions from fluxes"

8/14/08, 10:00 AM

W4

TBA

65. F. Marchesano: "Generalized non-supersymmetric flux vacua"

8/14/08, 10:30 AM

W4

I will discuss an strategy to construct 4D N=0 stable flux vacua of type II string theory, based on the existence of BPS bounds for probe D-branes in some of these backgrounds. In particular, I will consider compactifications where D-branes filling the 4D space-time obey the same BPS bound as they would in an N=1 compactification, while other D-branes, like those appearing as domain walls...

42. Morning coffee

8/14/08, 11:00 AM

W4

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.

69. C. Burgess: "Fibre Inflation and Tensor Perturbations in Type IIB Vacua"

8/15/08, 10:00 AM

W4

The talk presents an inflationary model of inflation in Type IIB string vacua, wherein the inflaton is a Kahler modulus of a K3 fibration Calabi Yau. It arises within the large-volume framework and so is closely related to Kahler modulus inflation models, and shares with these the property that the slow roll is not achieved by tuning parameters in the potential. But unlike the...

72. Discussion Session: Strings vs. LHC

8/15/08, 10:30 AM

This will be an informal discussion on the status of string theory at the dawn of the LHC, and about the possible impact of coming experimental data.

43. Morning coffee

8/15/08, 11:30 AM

W4

We meet at 11:00h in the discussion room in front of the TH Secretariat (building 4, second floor), to discuss informally over coffee.