M(atrix) Theory of Anti-zero-branes

M(atrix) theory defines light-front description of the boosted M-theory along the eleventh Mcoordinate. Rank of M(atrix) gauge group U(N) is directly related to the momentum along M-coordinate P11 = N/R11 or, equivalently, the number of D0-partons. Alternatively, Mtheory may be boosted to opposite direction of eleventh M-coordinate. We argue that the corresponding M(atrix) theory is described via anti-D0 partons so that M(atrix) gauge group becomes U(−N). Similarly reversed M(atrix) theory with eight superchrages are described by gauge group O(−2N) and USp(−2N). Gauge and supersymmetry anomaly cancellations require introduction of negative number of twisted sector matter multiplets. This is interpreted as 1 Work supported in part by the NSF-KOSEF Bilateral Grant, KOSEF SRC-Program, Ministry of Education Grant BSRI 97-2418 and the Korea Foundation for Advanced Studies. M(atrix) theory is the light-front description of boosted M-theory along eleventh M-coordinate. The argument that leads to the identification of D0-partons is as follows. Consider, in M-theory, a particle excitation of rest mass m: E − P 2 11 −P 2 ⊥ = m. (1) If the excitation is boosted by P11 = N/R along compactified eleventh M-coordinates of radius R, E − |P11| = 1 (E + |P11| (