String Theories on the Asymmetric Orbifolds with Twist-Untwist Intertwining Currents
نویسندگان
چکیده
We give various examples of asymmetric orbifold models to possess intertwining currents which convert untwisted string states to twisted ones, and vice versa, and see that such asymmetric orbifold models are severely restricted. The existence of the intertwining currents leads to the enhancement of symmetries in asymmetric orbifold models. ∗ To appear in the proceedings of YITP Workshop on “Recent Developments in String and Field Theory” at Kyoto, Japan on September 9-12, 1991.
منابع مشابه
Symmetries between Untwisted and Twisted Strings on Asymmetric Orbifolds
We study symmetries between untwisted and twisted strings on asymmetric orbifolds. We present a list of asymmetric orbifold models to possess intertwining currents which convert untwisted string states to twisted ones, and vice versa. We also present a list of heterotic strings on asymmetric orbifolds with supersymmetry between untwisted and twisted string states. Some of properties inherent in...
متن کاملThe General Class of String Theories on Orbifolds
We investigate the following three consistency conditions for constructing string theories on orbifolds: i) the invariance of the energy-momentum tensors under twist operators, ii) the duality of amplitudes and iii) modular invariance of partition functions. It is shown that this investigation makes it possible to obtain the general class of consistent orbifold models, which includes a new clas...
متن کاملOpen Strings in Magnetic Background Fields
We discuss various aspects of internal magnetic background fields in open string theories. Phenomenologically and conceptually interesting properties of such string theory backgrounds, supersymmetry and gauge symmetry breaking, chiral fermion spectra and noncommutativity of the internal compactification manifolds, are treated in a rather generic framework. We then specialize to type I compactif...
متن کاملDiagrams for Symmetric Product Orbifolds
We develop a diagrammatic language for symmetric product orbifolds of two-dimensional conformal field theories. Correlation functions of twist operators are written as sums of diagrams: each diagram corresponds to a branched covering map from a surface where the fields are single-valued to the base sphere where twist operators are inserted. This diagrammatic language facilitates the study of th...
متن کاملOn Four-Dimensional Gauge Theories from Type II Superstrings
We study the four-dimensional gauge theories which are associated with classical vacua of the type II superstring, i.e. which correspond to a superconformal field theory on the world sheet. Using the fact that gauge symmetry arises from a supersymmetric affine Kac-Moody algebra, and demanding unitarity of the underlying world-sheet field theory, we show that no such vacua can yield the particle...
متن کامل