Testing the Titius-Bode law predictions for Kepler multi-planet systems
  We use three and half years of Kepler Long Cadence data to search for the 97 predicted planets of Bovaird & Lineweaver (2013) in 56 of the multi-planet systems, based on a general Titius-Bode relation. Our search yields null results in the majority of systems. We detect five planetary candidates around their predicted periods. We also find an additional transit signal beyond those predicted in these systems. We discuss the possibility that the remaining predicted planets are not detected in the Kepler data due to their non-coplanarity or small sizes. We find that the detection rate is beyond the lower boundary of the expected number of detections, which indicates that the prediction power of the TB relation in general extra solar planetary systems is questionable. Our analysis of the distribution of the adjacent period ratios of the systems suggests that the general Titius-Bode relation may over-predict the presence of planet pairs near the 3:2 resonance. 
Chelsea X. Huang and G\'asp\'ar \'A. Bakos
astro-ph.EP