An astrophysical interpretation of the remarkable g-mode frequency groups of the rapidly rotating γ Dor star, KIC 5608334

The Fourier spectrum of the gamma-Dor variable KIC 5608334 shows remarkable frequency groups at similar to 3, similar to 6, similar to 9, and 11-12 d(-1). We explain the four frequency groups as prograde sectoral g modes in a rapidly rotating star. Frequencies of intermediate-to-high radial order prograde sectoral g modes in a rapidly rotating star are proportional to |m| (i.e. nu alpha |m|) in the corotating frame as well as in the inertial frame. This property is consistent with the frequency groups of KIC 5608334 as well as the period versus period-spacing relation present within each frequency group, if we assume a rotation frequency of 2.2 d(-1), and that each frequency group consists of prograde sectoral g modes of |m| = 1, 2, 3, and 4, respectively. In addition, these modes naturally satisfy near-resonance conditions nu(i) approximate to nu(j) +nu(k) with m(i) = m(j) + m(k). We even find exact resonance frequency conditions (within the precise measurement uncertainties) in many cases, which correspond to combination frequencies.