Liu Chen (; born 1946 in Hangzhou, Zhejiang) is an American theoretical physicist who has made original contributions to many aspects of plasma physics. He is known for the discoveries of kinetic Alfven waves, toroidal Alfven eigenmodes, and energetic particle modes; the theories of geomagnetic pulsations, Alfven wave heating, and fishbone oscillations, and the first formulation of nonlinear gyrokinetic equations. Chen retired from University of California, Irvine (UCI) in 2012, assuming the title Professor Emeritus of physics and astronomy. Biography Chen was born in 1946 in Hangzhou with ancestral roots in Yuyao. Chen's ancestral family name is Huang (黃), he is a descendant of Chengliang Huang (黃澄量), founder of the Five-Osmanthus Building (五桂樓）library, and the great scholar and thinker Zongxi Huang (黃宗羲). His great-grandfather, Chengyi Huang (黃承乙) was the mayor of Taiwan County, now Taichung City (台中市), during the Guangxu period of the Qing dynasty. In 1950, after the defeat of the Nationalists by the Communists in the Chinese Civil War, Chen left Mainland China with his mother, Shyue Yan King Chen (金學言, 1916–2006), and three siblings. They joined his father, Lee Chen (陳禮, 1913–2003), at the Tiu Keng Leng refugee camp in Hong Kong, where he began his education. The Chen family moved to Taiwan in 1951. Chen was married to Shingshah Lee (李醒夏) in August 1969. They have one son Peijin (陳培進). Chen graduated from the Affiliated Senior High School of National Taiwan Normal University in 1962. In 1966, he took his undergraduate degree at National Taiwan University. Chen went to United States for graduate schooling in 1967, where he obtained a Master of Science Degree from Washington State University, Pullman in 1969, and a Doctor of Philosophy Degree from the University of California, Berkeley under the supervision of Charles K. Birdsall in 1972, for his research work I. Heating of Magnetized Plasmas by Large-Amplitude Electric Field. II. Reduction of the Grid Effects in Simulation Plasmas. From 1972 to 1974, Chen did his postdoctoral research with Akira Hasegawa at the Bell Labs. They developed a theory for long-period magnetic pulsations in the magnetosphere based on resonant coupling between hydromagnetic compressional waves and transverse Alfvén continuous spectrum. This theory, later referred to as Chen-Hasegawa field-line-resonance model, successfully explained the observations in the Earth's magnetosphere by Louis J. Lanzerotti, and has become the standard model for magnetic pulsations in the Earth's and other planetary magnetospheres. Soon, their focus turned to