“…Since then, inspired by Dempster (1972), outstanding achievements have been made. Among them, Whittaker (1990), Edward (2000), Meinshausen and Buhlmann (2006), Yuan and Lin (2007), Peng et al (2009), Rothman et al (2010), Bien and Tibshirani (2011), Cai and Yuan (2012) and Chandrasekaran et al (2012) are often referred. Also, noticeable results on the distribution of the largest eigenvalue of the sample covariance matrix under various assumptions are done by Johnstone (2001Johnstone ( , 2008, Bickel and Levina (2008), Rothman et al (2009), Cai and Liu (2011), Cai and Zhou (2012 and Birnbaum et al (2013).…”