Flipped SU(5) predicts δT/T

Abstract: We discuss hybrid inflation in supersymmetric flipped model such that the cosmic microwave anisotropy is essentially proportional to , where M denotes the symmetry breaking scale and () is the reduced Planck mass. The magnitude of M determined from measurements can be consistent with the value inferred from the evolution of and gauge couplings. In other words, one could state that flipped predicts (more precisely ‘postdicts’) . The scalar spectral index , the scalar to tensor ratio satisfies , while . [Copyright &y& Elsevier]