Strings in Singular Time - Dependent Backgrounds 1
نویسندگان
چکیده
We review the construction of time-dependent backgrounds with space-like singularities. We mainly consider exact CFT backgrounds. The algebraic and geometric aspects of these backgrounds are discussed. Physical issues, results and difficulties associated with such systems are reviewed. Finally, we present some new results: a two dimensional cosmology in the presence of an Abelian gauge field described within a family of SL(2)×U(1) U(1)×Z quotient CFTs.
منابع مشابه
On the Hagedorn Behaviour of Singular Scale-Invariant Plane Waves
As a step towards understanding the properties of string theory in time-dependent and singular spacetimes, we study the divergence of density operators for string ensembles in singular scale-invariant plane waves, i.e. those plane waves that arise as the Penrose limits of generic spacetime singularities. We show that the scale invariance implies that the Hagedorn behaviour of bosonic and supers...
متن کاملD1-brane with Overcritical Electric Field in AdS3 and S-brane
We study aspects of Dirichlet S-branes, which are defined as Dirichlet boundary condition on a time like embedding of open strings, in general backgrounds. By applying T -duality along an isometry of the unphysical dS2-branes in NS-NS supported AdS3-background, we find S0-brane. We also study the time dependent tachyon condensation on the unstable Dp-brane and interpret the singular solutions a...
متن کاملQuotients of anti - de Sitter space
We study the quotients of n + 1-dimensional anti-de Sitter space by oneparameter subgroups of its isometry group SO(2, n) for general n. We classify the different quotients up to conjugation by O(2, n). We find that the majority of the classes exist for all n ≥ 2. There are two special classes which appear in higher dimensions: one for n ≥ 3 and one for n ≥ 4. The description of the quotient in...
متن کاملThe Dual Faces of String
Duality symmetries for strings moving in non-trivial spacetime backgrounds are analysed. It is shown that, for backgrounds generated from compact WZW and coset models, such duality symmetries are exact to all orders in string perturbation theory. A global treatment of duality symmetries is given, by associating them to the known symmetries of affine current algebras ( affine-Weyl group and exte...
متن کاملDuality Symmetries and Topology Change in String Theory
Duality symmetries for strings moving in non-trivial spacetime backgrounds are analysed. It is shown that for backgrounds generated from WZW and coset CFT models such duality symmetries are exact to all orders in string perturbation theory. Their implications for string dynamics in non-trivial/singular spacetimes are discussed. CERN-TH.7003/93 September 1993 ∗ Talk given at the EPS 93 Conferenc...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2003