10 citations · 49 across the 14 of their papers we have counts for
15 papers
Notions of Higher Type
Andreea C. Nicoara
Notions of finite type play an important role in several complex variables. The most standard notion is D'Angelo type, which measures the order of contact of holomorphic curves wit…
Sums of squares in pseudoconvex hypersurfaces and torsion phenomena for Catlin's boundary systems
Alexander Basyrov, Andreea C. Nicoara, Dmitri Zaitsev
Given a pseudoconvex hypersurface in C^n and an arbitrary weight, we show the existence of local coordinates in which the polynomial model contains a particularly simple sum of squ…
Relating Catlin and D'Angelo -types
Vasile Brinzanescu, Andreea C. Nicoara
We clarify the relationship between the two most standard measurements of the order of contact of q-dimensional complex varieties with a real hypersurface, the Catlin and D'Angelo…
A global Nullstellensatz for ideals of Denjoy-Carleman functions
Francesca Acquistapace, Fabrizio Broglia, Andreea Nicoara
We prove a Nullstellensatz result for global ideals of Denjoy-Carleman functions in both finitely generated and infinitely generated cases.
Direct Proof of Termination of the Kohn Algorithm in the Real-Analytic Case
Andreea C. Nicoara
In 1979 J.J. Kohn gave an indirect argument via the Diederich-Fornæss Theorem showing that finite D'Angelo type implies termination of the Kohn algorithm for a pseudoconvex domain…
Coherence and Other Properties of Sheaves in the Kohn Algorithm
Andreea C. Nicoara
In the smooth case, we prove quasi-flasqueness for the sheaves of all subelliptic multipliers as well as at each of the steps of the Kohn algorithm on a pseudoconvex domain in $\C^…
On the Relationship between D'Angelo q-type and Catlin q-type
Vasile Brinzanescu, Andreea C. Nicoara
We establish inequalities relating two measurements of the order of contact of q-dimensional complex varieties with a real hypersurface.
Failure of the Weierstrass Preparation Theorem in quasi-analytic Denjoy-Carleman rings
Francesca Acquistapace, Fabrizio Broglia, Michail Bronshtein +2
It is shown that Denjoy-Carleman quasi-analytic rings of germs of functions in two or more variables fail to satisfy the Weierstrass Preparation Theorem. The result is proven via a…
A Nullstellensatz for Łojasiewicz ideals
Francesca Acquistapace, Fabrizio Broglia, Andreea Nicoara
For an ideal of smooth functions that is either Łojasiewicz or weakly Łojasiewicz, we give a complete characterization of the ideal of functions vanishing on its variety in terms o…
Non-Noetherianity of Denjoy-Carleman rings of germs
Liat Kessler, Andreea C. Nicoara
It is shown that Denjoy-Carleman quasi analytic rings of germs of functions in two or more variables either complex or real valued that are stable under derivation and strictly lar…
Effective vanishing order of the Levi determinant
Andreea C. Nicoara
On a smooth domain in complex n space of finite D'Angelo q-type at a point, an effective upper bound for the vanishing order of the Levi determinant $\text{coeff}\{\partial r \wedg…
The Kohn Algorithm on Denjoy-Carleman Classes
Andreea C. Nicoara
The equivalence of the Kohn finite ideal type and the D'Angelo finite type with the subellipticity of the -Neumann problem is extended to pseudoconvex domains in $C^n…
Equivalence of types and Catlin boundary systems
Andreea C. Nicoara
The D'Angelo finite type is shown to be equivalent to the Kohn finite ideal type on smooth, pseudoconvex domains in complex n space. This is known as the Kohn Conjecture. The argum…
The \bar\partial_b Equation on Weakly Pseudoconvex CR Manifolds of Dimension 3
Joseph J. Kohn, Andreea Nicoara
Let M be a smooth, compact, orientable, weakly pseudoconvex manifold of dimension 3, embedded in C^N (N greater than or equal to 2), of codimension one or more in C^N, and endowed…
Global Regularity for the Tangential Cauchy-Riemann Operator on Weakly Pseudoconvex CR Manifolds
Andreea Nicoara
Let M of real dimension 2n-1 be a compact, orientable, weakly pseudoconvex manifold of dimension at least five, embedded in C^N (n less than or equal to N), of codimension one or m…