Real forms of smooth del Pezzo surfaces.
Real hypersurfaces with many simple singularities.
In this paper we present constructions of real hypersurfaces with many simple singularities and deduce an asymptotical optimal existence result for hypersurfaces corresponding to T-smooth germs of the equisingular stratum. We proceed along the lines of Shustin-Westenberge (2004) where analogous results were shown for the complex case.
Real Kodaira surfaces.
In this paper we give the topological classification of real primary Kodaira surfaces and we describe in detail the structure of the corresponding moduli space. Moreover, we use the notion of the orbifold fundamental group of a real variety, which was also the main tool in the classification of real hyperelliptic surfaces achieved in [10]. Our first result is that if (S,sygma) is a real primary Kodaira surface, then the differentiable tupe of the pair (S,sygma) is completely determined by the orbifold...
Real Moduli of Complex Objects: Surfaces and Bundles.
Real points on complex plane curves.
Real projective structures on Riemann surfaces
Real quartic surfaces containing 16 skew lines.
Real Schubert calculus: polynomial systems and a conjecture of Shapiro and Shapiro.
Real singular Del Pezzo surfaces and 3-folds fibred by rational curves, II
Let be a real smooth projective 3-fold fibred by rational curves such that is orientable. J. Kollár proved that a connected component of is essentially either Seifert fibred or a connected sum of lens spaces. Answering three questions of Kollár, we give sharp estimates on the number and the multiplicities of the Seifert fibres (resp. the number and the torsions of the lens spaces) when is a geometrically rational surface. When is Seifert fibred over a base orbifold , our result generalizes...
Real spectra of complete local rings.
Real theta-characteristics on real projective curves.
Real Zeros of Positive Semidefinite Forms. I.
Realization of Hölder complexes
Realization of homotopy classes by algebraic mappings.
Reconstruction of algebraic sets from dynamic moments
We discuss an exact reconstruction algorithm for time expanding semi-algebraic sets given by a single polynomial inequality. The theoretical motivation comes from the classical -problem of moments, while some possible applications to 2D fluid moving boundaries are sketched. The proofs rely on an adapted co-area theorem and a Hankel form minimization.
Rectilinearization of functions definable by a Weierstrass system and its applications
This paper presents several theorems on the rectilinearization of functions definable by a convergent Weierstrass system, as well as their applications to decomposition into special cubes and quantifier elimination.
Reduction of semialgebraic constructible functions
Let R be a real closed field with a real valuation v. A ℤ-valued semialgebraic function on Rⁿ is called algebraic if it can be written as the sign of a symmetric bilinear form over R[X₁,. .., Xₙ]. We show that the reduction of such a function with respect to v is again algebraic on the residue field. This implies a corresponding result for limits of algebraic functions in definable families.
Reduction of the singularities of foliations and applications
Reduction theorems for the Strong Real Jacobian Conjecture
Implementations of known reductions of the Strong Real Jacobian Conjecture (SRJC), to the case of an identity map plus cubic homogeneous or cubic linear terms, and to the case of gradient maps, are shown to preserve significant algebraic and geometric properties of the maps involved. That permits the separate formulation and reduction, though not so far the solution, of the SRJC for classes of nonsingular polynomial endomorphisms of real n-space that exclude the Pinchuk counterexamples to the SRJC,...
Regular analytic transformations of
Existence of loops for non-injective regular analytic transformations of the real plane is shown. As an application, a criterion for injectivity of a regular analytic transformation of in terms of the Jacobian and the first and second order partial derivatives is obtained. This criterion is new even in the special case of polynomial transformations.