...http://www-dft.ts.infn.it/ ansoldi¹

E-mail address: ansoldi@trieste.infn.it

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...A.Aurilia²

E-mail address: aaurilia@csupomona.edu

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...http://www-dft.ts.infn.it/ euro³

E-mail address: spallucci@vstst0.ts.infn.it

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... well⁴

Note the ``Mach-ian flavor'' of this new definition or position and time: spacetime coordinates are not defined by themselves but only in terms of objects located at a given point. This operative definition of coordinates as labels of some material stuff seems even more appropriate in $M$-Theory where spacetime itself is in some way built out of fundamental strings, or branes, or matrices, or ...something else.

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... superstrings⁵

A similar matrix action for the Type $IIA$ model has been conjectured in [14].

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... bracket⁶

This is not the canonical Poisson bracket which is replaced by the quantum mechanical commutator. Rather, it is the world sheet sylleptic structure which is replaced by the (classical) matrix commutator for finite $N$.

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... momentum⁷

$[ \Lambda ] = (length) ^{2}$. Accordingly, the loop wavelength is strictly given by $\sqrt \Lambda$.

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