Cosmological Unification of String Theories Simeon Hellerman based on : hep-th/0611317, S.H. and Ian Swanson hep-th/0612051, S.H. and Ian Swanson hep-th/0612116, S.H. and Ian Swanson arXiv:0705.0980, S.H. and Ian Swanson arXiv:0709.2166, S.H. and Ian Swanson arXiv:0710.1628, S.H. and Ian Swanson and work in progress Strings 2008, CERN, Geneva, August 22, 2008 Outline Bosonic string solutions with nonzero tachyon Dimension-changing solutions in the bosonic string Transitions from type 0 to type II string theory Lightlike tachyon condensation in Type 0 Other examples Conclusions Cosmological Unification of String Theories Simeon Hellerman based on : hep-th/0611317, S.H. and Ian Swanson hep-th/0612051, S.H. and Ian Swanson hep-th/0612116, S.H. and Ian Swanson arXiv:0705.0980, S.H. and Ian Swanson arXiv:0709.2166, S.H. and Ian Swanson arXiv:0710.1628, S.H. and Ian Swanson and work in progress Strings 2008, CERN, Geneva, August 22, 2008 Outline Bosonic string solutions with nonzero tachyon Dimension-changing solutions in the bosonic string Transitions from type 0 to type II string theory Lightlike tachyon condensation in Type 0 Other examples Conclusions Introduction We understand THIS very well: Introduction We understand THIS very well: We also understand perturbations by weak SUSY breaking – Introduction We understand THIS very well: Introduction We understand THIS very well: We also understand perturbations by weak SUSY breaking – Introduction We understand THIS very well: We also understand perturbations by weak SUSY breaking – ! Anti-D-branes Introduction We understand THIS very well: We also understand perturbations by weak SUSY breaking – ! Anti-D-branes ! Fluxes Introduction We understand THIS very well: We also understand perturbations by weak SUSY breaking – ! Anti-D-branes Introduction We understand THIS very well: We also understand perturbations by weak SUSY breaking – ! Anti-D-branes ! Fluxes Introduction We understand THIS very well: We also understand perturbations by weak SUSY breaking – ! Anti-D-branes ! Fluxes We don’t yet understand strong SUSY breaking very well! Introduction GOALS: ! Understand cosmology and strong time dependence Introduction We understand THIS very well: We also understand perturbations by weak SUSY breaking – ! Anti-D-branes ! Fluxes We don’t yet understand strong SUSY breaking very well! Introduction GOALS: ! Understand cosmology and strong time dependence Introduction GOALS: ! Understand cosmology and strong time dependence ! Understand strong SUSY breaking Introduction GOALS: ! Understand cosmology and strong time dependence ! Understand strong SUSY breaking ! Understand connections between string theories – each of the possible 10500 universes should contain all the others! Introduction GOALS: ! Understand cosmology and strong time dependence ! Understand strong SUSY breaking Introduction GOALS: ! Understand cosmology and strong time dependence ! Understand strong SUSY breaking ! Understand connections between string theories – each of the possible 10500 universes should contain all the others! Introduction GOALS: ! Understand cosmology and strong time dependence ! Understand strong SUSY breaking ! Understand connections between string theories – each of the possible 10500 universes should contain all the others! Each of these questions is related to the others –ifweunderstand one, we will understand all of them. Introduction GOALS: ! Understand cosmology and strong time dependence ! Understand strong SUSY breaking ! Understand connections between string theories – each of the possible 10500 universes should contain all the others! Each of these questions is related to the others –ifweunderstand one, we will understand all of them. What are the simplest concrete models of connections and transitions? Introduction GOALS: ! Understand cosmology and strong time dependence ! Understand strong SUSY breaking ! Understand connections between string theories – each of the possible 10500 universes should contain all the others! Each of these questions is related to the others –ifweunderstand one, we will understand all of them. Introduction GOALS: ! Understand cosmology and strong time dependence ! Understand strong SUSY breaking ! Understand connections between string theories – each of the possible 10500 universes should contain all the others! Each of these questions is related to the others –ifweunderstand one, we will understand all of them. What are the simplest concrete models of connections and transitions? What I will describe today What I will describe today ! Aclassofα!-exact classical solutions of string theory What I will describe today What I will describe today ! Aclassofα!-exact classical solutions of string theory What I will describe today ! Aclassofα!-exact classical solutions of string theory ! With D not necessarily equal to 10 or 26 What I will describe today ! Aclassofα!-exact classical solutions of string theory ! With D not necessarily equal to 10 or 26 ! D changes dynamically What I will describe today ! Aclassofα!-exact classical solutions of string theory ! With D not necessarily equal to 10 or 26 What I will describe today ! Aclassofα!-exact classical solutions of string theory ! With D not necessarily equal to 10 or 26 ! D changes dynamically What I will describe today ! Aclassofα!-exact classical solutions of string theory ! With D not necessarily equal to 10 or 26 ! D changes dynamically ! Spacetime SUSY changes dynamically What I will describe today ! Aclassofα!-exact classical solutions of string theory ! With D not necessarily equal to 10 or 26 ! D changes dynamically ! Spacetime SUSY changes dynamically ! Worldsheet SUSY changes dynamically What I will describe today ! Aclassofα!-exact classical solutions of string theory ! With D not necessarily equal to 10 or 26 ! D changes dynamically ! Spacetime SUSY changes dynamically What I will describe today ! Aclassofα!-exact classical solutions of string theory ! With D not necessarily equal to 10 or 26 ! D changes dynamically ! Spacetime SUSY changes dynamically ! Worldsheet SUSY changes dynamically What I will describe today ! Aclassofα!-exact classical solutions of string theory ! With D not necessarily equal to 10 or 26 ! D changes dynamically ! Spacetime SUSY changes dynamically ! Worldsheet SUSY changes dynamically ! All involve closed string tachyon condensation, treated exactly in α! and in the tachyon strength. What I will describe today ! Aclassofα!-exact classical solutions of string theory ! With D not necessarily equal to 10 or 26 ! D changes dynamically ! Spacetime SUSY changes dynamically ! Worldsheet SUSY changes dynamically ! All involve closed string tachyon condensation, treated exactly in α! and in the tachyon strength. THIS TALK IS A CONJECTURE-FREE ZONE! What I will describe today ! Aclassofα!-exact classical solutions of string theory ! With D not necessarily equal to 10 or 26 ! D changes dynamically ! Spacetime SUSY changes dynamically ! Worldsheet SUSY changes dynamically ! All involve closed string tachyon condensation, treated exactly in α! and in the tachyon strength. What I will describe today ! Aclassofα!-exact classical solutions of string theory ! With D not necessarily equal to 10 or 26 ! D changes dynamically ! Spacetime SUSY changes dynamically ! Worldsheet SUSY changes dynamically ! All involve closed string tachyon condensation, treated exactly in α! and in the tachyon strength. THIS TALK IS A CONJECTURE-FREE ZONE! Analogy with open string tachyon dynamics D-brane decay Analogy with open string tachyon dynamics D-brane decay Solitons Analogy with open string tachyon dynamics D-brane decay Analogy with open string tachyon dynamics D-brane decay Solitons Parallel with Open String Tachyon Dynamics An analogy arises for the (bosonic) closed string tachyon, representing an instability of spacetime itself. Outline Bosonic string solutions with nonzero tachyon Dimension-changing solutions in the bosonic string Transitions from type 0 to type II string theory Lightlike tachyon condensation in Type 0 Other examples Conclusions Parallel with Open String Tachyon Dynamics An analogy arises for the (bosonic) closed string tachyon, representing an instability of spacetime itself. Outline Bosonic string solutions with nonzero tachyon Dimension-changing solutions in the bosonic string Transitions from type 0 to type II string theory Lightlike tachyon condensation in Type 0 Other examples Conclusions Tachyonic perturbations We are interested in tachyonic perturbations of unstable string theories. In the bosonic string, for instance, the tachyon (X ) T couples to the worldsheet as a normal-ordered potential : (X ):. T Tachyonic perturbations We are interested in tachyonic perturbations of unstable string theories. In the bosonic string, for instance, the tachyon (X ) T couples to the worldsheet as a normal-ordered potential : (X ):. T We will now discuss a large class of solvable and exactly marginal perturbations of this form. Tachyonic perturbations We are interested in tachyonic perturbations of unstable string theories. In the bosonic string, for instance, the tachyon (X ) T couples to the worldsheet as a normal-ordered potential : (X ):. T Tachyonic perturbations We are interested in tachyonic perturbations of unstable string theories. In the bosonic string, for instance, the tachyon (X ) T couples to the worldsheet as a normal-ordered potential : (X ):. T We will now discuss a large class of solvable and exactly marginal perturbations of this form. Bubble of nothing Consider a theory