Geometry on string lattice

Using the method developed by Callan and Thorlacius, we study the low energyeffective geometry on a two-dimensional string lattice by examining theenergy-momentum relations of the low energy propagation modes on the lattice.We show that the geometry is identical for both the oscillation modes tangentand transverse to the network plane. We determine the relation between thegeometry and the lattice variables. The lowest order effective field theory isgiven by the dimensional reduction of the ten-dimensional N=1 Maxwell theory.The gauge symmetry is related to a property of a three-string junction but notof a higher order junction. A half of the supersymmetries in the effectivefield theory should be broken at high energy.Comment: 13 pages, no figures, LaTe