EN
We consider the systems of hyperbolic equations
⎧$uₜₜ = Δ(a(t,x)u) + Δ(b(t,x)v) + h(t,x)|v|^{p}$, t > 0, $x ∈ ℝ^{N}$, (S1)
⎨
⎩$vₜₜ = Δ(c(t,x)v) + k(t,x)|u|^{q}$, t > 0, $x ∈ ℝ^{N}$
⎧$uₜₜ = Δ(a(t,x)u) + h(t,x)|v|^{p}$, t > 0, $x ∈ ℝ^{N}$, (S2)
⎨
⎩$vₜₜ = Δ(c(t,x)v) + l(t,x)|v|^{m} + k(t,x)|u|^{q}$, t > 0, $x ∈ ℝ^{N}$, (S3)
⎧$uₜₜ = Δ(a(t,x)u) + Δ(b(t,x)v) + h(t,x)|u|^{p}$, t > 0, $x ∈ ℝ^{N}$,
⎨
⎩$vₜₜ = Δ(c(t,x)v) + k(t,x)|v|^{q}$, t > 0, $x ∈ ℝ^{N}$,
in $(0,∞) × ℝ^{N}$ with u(0,x) = u₀(x), v(0,x) = v₀(x), uₜ(0,x) = u₁(x), vₜ(0,x) = v₁(x). We show that, in each case, there exists a bound B on N such that for 1 ≤ N ≤ B solutions to the systems blow up in finite time.