Sign Choices for Orientifolds

Brane Tilings for Orientifolds

Brane tilings, often also refered to as dimers, are currently the most powerful tool available to study the 4D low-energy effective gauge theories arising from D3-branes at toric Calabi-Yau 3-fold singularities. From a mathematical viewpoint, brane tilings are just bipartite graphs, there bipartite means that one can color the vertices of a graph with two colors (usually black and white) such t...

F Theory Orientifolds, M Theory Orientifolds, and Twisted Strings

Orientifolds of the type IIB superstring that descend from F theory and M theory orbifolds are studied perturbatively. One finds strong evidence that a previously ignored twisted open string is required in these models. An attempt is made to interpret the J type torsion in F theory where one finds a realization of Gimon and Johnson’s models which does not require these twisted strings. S-dualit...

Permutation Orientifolds

We consider orientifold actions involving the permutation of two identical factor theories. The corresponding crosscap states are constructed in rational conformal field theory. We study group manifolds, in particular the examples SU(2)×SU(2) and U(1)×U(1) in detail, comparing conformal field theory results with geometry. We then consider orientifolds of tensor products of N = 2 minimal models,...

Bilateral Schwartze Sign, Decision-Making for Surgery

Otosclerosis is an otic capsule disorder that leads to progressive conductive and/or sensorineural hearing loss due to stapes footplate fixation and cochlear bone involvement. The disorder is bilateral in 70% of patients and it usually starts between the third and fifth decade. One of its characteristic clinical findings is Schwartze sign which refers to a reddish discoloration over the promont...

Language Choices for Deaf Infants: Advice for Parents Regarding Sign Languages.