2017/10/10 by Yahaghi, Bamdad R.
#15A30 #20M20 #FOS: Mathematics #Rings and Algebras (math.RA)
paper · doi:10.48550/arxiv.1710.03849
In this note, we consider irreducible semigroups of real, complex, and quaternionic matrices with real spectra. We prove Burnside type theorems in the settings of reals and quaternions. First, we prove that an irreducible semigroup of triangularizable matrices in Mn(ℝ) contains a vector space basis for Mn(ℝ). In other words, Mn(ℝ) is the only irreducible subalgebra of itself that is spanned by an irreducible semigroup of triangularizable matrices in Mn(ℝ). Next, we use this result to show that, up to similarity, Mn(ℝ) is the only irreducible ℝ-algebra in Mn(ℍ) that is spanned by an irreducible semigroup of matrices in Mn(ℍ) with real spectra. Some consequences of our mains results are presented.