Unveiling the Hearts of Major Mergers with Laser Guide Star Adaptive Optics Anne Medling (UCSC) Major mergers are thought to be an important stage of galaxy evolution, and in gas-rich galaxies can instigate intense star formation and nuclear activity. Much of this activity goes on in the inner kiloparsec, which has been difficult to study due to resolution and extinction concerns. We present < 0.1"-resolution near-infrared integral field spectroscopy of the nuclear regions of nearby (U)LIRGs in late stages of merging. Our observations were taken with the OSIRIS spectrograph on the Keck II telescope, with laser guide star adaptive optics, and provide stellar and gas kinematics on scales of ~20-80 pc. In our sample, we find nuclear disks of stars and/or gas on scales of a few hundred parsecs around one or both nuclei in all nine of the merging systems observed. Binary black hole merger simulations suggest that the presence of these nuclear disks may be important for angular momentum loss and final coalescence. By studying the kinematics of these nuclear disks, we can also measure black hole masses in the midst of major mergers and trace galaxies' paths along black hole scaling relations to assess galaxy-bulge growth relations during this important stage of galaxy evolution. Our gas-rich mergers tend to lie above black hole scaling relations. To illustrate the richness of our dataset, we also present an in-depth picture for Mrk 273, in which we confirm the AGN found with Chandra and conclude that the second nucleus likely contains an obscured AGN as well.