9 citations · 9 across the 3 of their papers we have counts for
3 papers
math.AP2025
Notes on tangent bicharacteristics and ill-posedness of the Cauchy problem
Enrico Bernardi, Tatsuo Nishitani
We exhibit a family of second-order hyperbolic differential operators presenting spectral transition of the Hamilton map. As a consequence we prove that the Cauchy problem is not l…
math.AP2025
Geometric results for hyperbolic operators with spectral transition of the Hamilton map
Enrico Bernardi, Tatsuo Nishitani
In this paper we study a class of non-effectively hyperbolic operators vanishing of order 2 on a manifold, on a sub-region of which the spectral structure of the Hamilton map chang…
math.AP2013★ 9 cited
Cauchy problem for effectively hyperbolic operators with triple characteristics of variable multiplicity
Enrico Bernardi, Antonio Bove, Vesselin Petkov
We study a class of third order hyperbolic operators in with triple characteristics at $ρ= (0, x_0, ξ), ξ\in {…