Growth rate for endomorphisms of finitely generated nilpotent groups and   solvable groups
  We prove that the growth rate of an endomorphism of a finitely generated nilpotent group equals to the growth rate of induced endomorphism on its abelinization, generalizing the corresponding result for an automorphism in [14]. We also study growth rates of endomorphisms for specific solvable groups, lattices of Sol, providing a counterexample to a known result in [5] and proving that the growth rate is an algebraic number. 
Alexander Fel'shtyn, Jang Hyun Jo, Jong Bum Lee
math.GR math.DS