Two-dimensional topology of large-scale structure in the Las Campanas Redshift Survey

We have measured the topology (genus) of the density distribution of large-scale structure observed in the Las Campanas Redshift Survey (LCRS). The LCRS is complete to magnitude 17.5 and contains nearly 24,000 galaxies with median redshift of 30,000 km s(-1) The large volume and large number of galaxies permit sampling of nearly 100 independent structures with which to compute the genus topology, a vast improvement over previous studies. We find that the genus is consistent with a random-phase Gaussian distribution of initial density fluctuations, as would be produced naturally in inflationary models. When we combine these results with the genus measurements of the COBE microwave background fluctuations, we find that two orthogonal projections of the three-dimensional distribution of initial density fluctuations are consistent with Gaussian random-phase behavior, in agreement with standard inflationary models. Particular attention is given to statistical significance of the genus test.