This paper is addressed to some questions concerning the exponential stability and its robustness
measure for linear time-varying differential-algebraic systems of index 1. First, the Bohl exponent theory
that is well known for ordinary differential equations is extended to differential-algebraic equations. Then, it
is investigated that how the Bohl exponent and the stability radii with respect to dynamic perturbations for a
differential-algebraic system depend on the system data. The paper can be considered as a continued and
complementary part to a recent paper on stability radii for time-varying differential-algebraic equations
[N.H. Du, V.H. Linh, Stability radii for linear time-varying differential-algebraic equations with respect to
dynamic perturbations, J. Differential Equations 230 (2006) 579-599]. ?? 2008 Elsevier Inc. All rights
reserved.
