Large Structures and Galaxy Evolution in COSMOS at z < 1.1

We present the first identification of large-scale structures (LSS) at z $<1.1$ in the Cosmic Evolution Survey (COSMOS). The structures are identifiedfrom adaptive smoothing of galaxy counts in the pseudo-3d space($\alpha,\delta$,z) using the COSMOS photometric redshift catalog. Thetechnique is tested on a simulation including galaxies distributed in modelclusters and a field galaxy population -- recovering structures on all scalesfrom 1 to 20\arcmin without {\it a priori} assumptions for the structure sizeor density profile. Our procedure makes {\bf no} {\it a priori} selection ongalaxy spectral energy distribution (SED, for example the Red Sequence),enabling an unbiased investigation of environmental effects on galaxyevolution. The COSMOS photometric redshift catalog yields a sample of$1.5\times10^5$ galaxies with redshift accuracy, $\Delta z_{FWHM}/(1+z) \leq0.1$ at z $< 1.1$ down to I$_{AB} \leq 25$ mag. Using this sample of galaxies,we identify 42 large-scale structures and clusters. abstract truncated forastroph 25 line limit -- see preprintComment: 72 pages with 29 pages of figures, for cosmos apj suppl special issu