Brane fusion in the bosonic string and the emergence of fermionic strings

by Taormina, Anne (Durham)

Tuesday 14 Aug 2001, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

We review the emergence of the ten-dimensional fermionic closed string theories from subspaces of the Hilbert space of the 26-dimensional bosonic closed string theory compactified on an E_8 times SO (16) lattice. They arise from a consistent truncation procedure which generates space-time fermions out of bosons. This procedure is extended to open string sectors. We prove that truncation of the unique tadpole-free SO (2^13) bosonic string theory compactified on the above lattice determines the anomaly free Chan - Paton group of the Type I theory and the consistent Chan - Paton groups of Type 0 theories. It also predicts the tension of space-filling D-branes in these fermionic theories. The derivation of these fermionic string properties from bosonic considerations alone points towards a dynamical origin of the truncation process. Space-time fermions and supersymmetries would then arise from bosonic degrees of freedom and no fermionic degrees of freedom would be needed in a fundamental theory of quantum gravity.