Bulletin of the
Korean Mathematical Society BKMS

We consider $\mc T_\infty(F)$ -- the space of upper triangular infinite matrices over a field $F$. We investigate injective linear maps on this space which preserve the additivity of rank, i.e., the maps $\phi$ such that \linebreak $\rank(x+y)=\rank(x)+\rank(y)$ implies $\rank(\phi(x+y))=\rank(\phi(x))+\rank(\phi(y))$ for all $x$, $y\in\mc T_\infty(F)$.

Keywords: rank additivity, linear preserver problem, infinite triangular matrices

MSC numbers: 15A03, 15A04, 15A86