A New String in Ten Dimensions?

Abstract

I suggest the possibility of a new string in ten dimensions. Evidence for this string is presented both from orientifold physics and from K-theory, along with a mystery concerning the M-theory description. Motivated by this possibility, some novel aspects of decoupling limits in heterotic/type I theories are described; specifically, the decoupled theory on type I $D$-strings is argued to be three-dimensional rather than two-dimensional. These decoupled theories provide the matrix model definitions of the heterotic/type I strings.

18 pages, 2 figures; LaTeX; significant revision of the M-theory discussion; comments, caveats and references added

References in corpus (6)

• N=6 superconformal Chern-Simons-matter theories, M2-branes and their gravity duals
• Notes on gauging noneffective group actions
• Boundary Conditions for Interacting Membranes
• K-Theory in Quantum Field Theory
• GLSM's, gerbes, and Kuznetsov's homological projective duality
• The instability of orientifolds and the end of the (string) landscape as we know it

Cited by in corpus (9)

• Dai-Freed anomalies in particle physics
• Discrete theta and the 5d superconformal index
• Negative Branes, Supergroups and the Signature of Spacetime
• The anomaly that was not meant IIB
• IIB Explored: Reflection 7-Branes
• New Supersymmetric String Theories from Discrete Theta Angles
• Hierarchies of RG flows in 6d $(1,0)$ massive E-strings
• Domain Walls, Triples and Acceleration
• Open Strings and Heterotic Instantons