Bounds on the number of connected components for tropical prevarieties

Abstract

For a tropical prevariety in $R^n$ given by a system of $k$ tropical polynomials in $n$ variables with degrees at most $d$, we prove that its number of connected components is less than $\left(\genfrac{}{}{0ex}{}{k+7n-1}{3n}\right)\cdot \frac{d^{3n}}{k+n+1}$. On a number of $0$-dimensional connected components a better bound $\left(\genfrac{}{}{0ex}{}{k+4n}{3n}\right)\cdot \frac{d^n}{k+n+1}$ is obtained, which extends the Bezout bound due to B.~Sturmfels from the the case $k=n$ to an arbitrary $k\ge n$. Also we show that the latter bound is close to sharp, in particular, the number of connected components can depend on $k$.

References in corpus (1)

• Computing Tropical Varieties