Abstract:
We consider a system of $n$ algebraic equations in $n$ variables, where
the exponents of the monomials in each equation are fixed while all the
coefficients vary. The discriminant locus of such a system is
the closure of the set of all coefficients for which the system has
multiple roots with non-zero coordinates. For dehomogenized discriminant loci,
we give parametrizations of those irreducible components that depend
on the coefficients of all the equations. We prove that if such a component
has codimension 1, then the parametrization is inverse to the logarithmic
Gauss map of the component (an analogue of Kapranov's result for the
$A$-discriminant). Our argument is based on the linearization of algebraic
systems and the parametrization of the set of its critical values.
Keywords:discriminant locus, linearization of an algebraic system, logarithmic Gauss map.