Fractional Independence Number
The fractional independence number, denoted α^* (Shannon 1956, Acín et al. 2016) or α_f, also called the fractional packing number (Shannon 1956, Acín et al. 2016) or Rosenfeld number (Acín et al. 2016), is a graph parameter defined by relaxing the weight condition in the computation of the independence number from allowing only weights 0 and 1 to any real numbers in the interval [0, 1].