From: Higher order temporal finite element methods through mixed formalisms
Algorithms
Eigenvalues
Jquad
λ 1 , 2 = 6 m a - 2 h 2 ± i 36 h 2 m a - 3 h 4 6 m a + h 2
Uquad
UJquad
λ 1 , 2 = h 4 - 60 a m h 2 + 144 m 2 a 2 ± i 12 h 12 a m - h 2 a m h 4 + 12 a m h 2 + 144 m 2 a 2