We study the finiteness of range's codimension for a class of non-globally hypoelliptic vector
fields on a torus of dimension three. The linear dependence of certain interactions of the …

This paper deals with Gevrey global solvability on the N-dimensional torus (TN≃ RN/2 π ZN)
to a class of nonlinear first order partial differential equations in the form L u-au-bu¯= f …

This paper deals with semi-global C k-solvability of complex vector fields of the form L= ∂/∂
t+ x^ r (a (x)+ ib (x)) ∂/∂ x,, r≥ 1, defined on\Omega_ ϵ=(-ϵ, ϵ) * S^ 1, ϵ> 0, where a and b …

We consider smooth, nonvanishing complex (not essentially real) vector fields L= X+ i Y that
satisfy the Nirenberg-Treves condition (P) and are allowed to possess some closed one …

We study the Gevrey solvability of a class of complex vector fields, defined on Ωϵ=(− ϵ, ϵ)×
S1, given by L=∂/∂ t+ (a (x)+ ib (x))∂/∂ x, b≢ 0, near the characteristic set Σ={0}× S1. We …

In this work we deal with solvability of first‐order differential equations in the form, where L is
a planar complex vector field, elliptic everywhere except along a simple closed curve Σ on …

This work deals with the solvability near the characteristic set Σ= 0× S 1 of operators of the
form L= ∂/∂ t+(x^ na (x)+ ix^ mb (x)) ∂/∂ x, b\not\equiv0 and a (0)≠ 0, defined on\Omega …

This work deals with global solvability of a class of vector fields of the form L=∂/∂ t+(a (x)+
ib (x))(∂/∂ x+ λ∂/∂ y), where a, b∈ C∞(T 1, R) and λ∈ R, defined on the three …

The vector field (1.1) is a model of a class of rotationally invariant complex vector fields of
infinite type along a closed smooth curve. For further information on these concepts and …

We deal with solvability in Denjoy-Carleman classes of complex vector fields defined on Ω=
R× S1, given by L=∂/∂ t+(a (x, t)+ ib (x, t))∂/∂ x, b≡ 0, near the characteristic set Σ={0}× …