Abstract:
We consider a class of scalar linear differential equations with several variable delays and constant coefficients. A family of equations of the class is defined by coefficients and maximum addmissible values of delays. We investigate domains in the parameter space, whose points correspond to families of equations that possess certain properties, which are uniform and exponential stabilities of solutions, and the property of the fundamental solution of an equation to have fixed sign. Necessary and sufficient conditions for a family of equations to have these properties are obtained in the explicit form.
Keywords:functional differential equation, varying delay, several delays, fixed sign, stability, fundamental solution.