M(atrix) theory on T5Z2 orbifold and five-branes Original Research Article

We study the M(atrix) theory description of M-theory compactified on a T5Z2 orbifold. In the large volume limit we show that M-theory dynamics is described by N = 8 supersymmetric USp(2N) M(atrix) quantum mechanics. Via zero-brane parton scattering, we show that each orbifold fixed point carries an anomalous G-flux ∲[G/2π]= −12. To cancel the anomalous G-flux, we introduce a twisted sector consisting of sixteen five-branes represented by fundamental representation hypermultiplets. In the small volume limit we show that M-theory dynamics is effectively described by (5 + 1)-dimensional (8,0) supersymmetric USp(2N) chiral gauge theory. We point out that both perturbative and global gauge anomalies are cancelled by the sixteen fundamental representation hypermultiplets in the twisted sector. We show that M(atrix) theory is capable of turning on a space-time background with the required sixteen five-branes out of zero-brane partons as bound states. We determine the six-dimensional space-time spectrum from the M(atrix) theory for both untwisted and twisted sectors and find a complete agreement with the spectrum of (2, 0) supergravity. We discuss the M(atrix) theory description of compactification moduli space, symmetry enhancement thereof as well as further toroidal compactifications.