A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.
We show that totally real elliptic Lefschetz fibrations that admit a real section are classified by their "real loci" which is nothing but an S1-valued Morse function on the real part of the total space. We assign to each such real locus a certain combinatorial object that we call a \emph{necklace diagram}. On the o…
The following results are proved: Theorem 1. A totally real semiparallel submanifold of constant curvature with parallel f-structure in the normal bundle of a Kähler manifold N is flat or a totally geodesic submanifold of N. Theorem 2. A totally real minimal semiparallel submanifold M with parallel f-structure in the n…
Totally real immersions f of a closed real surface Σ in an almost complex surface M are completely classified, up to homotopy through totally real immersions, by suitably defined homotopy classes M(f) of mappings from Σ into a specific real 5-manifold E(M), while M(f) themselves are subject …
In this paper we investigate what kind of manifolds arise as the total spaces of iterated S1-bundles. A real Bott tower studied in \cite{CMO}, \cite{KM} and \cite{KN} is an example of an iterated S1-bundle. We show that the total space of an iterated S1-bundle is homeomorphic to an infra-nilmanifold. A real Bo…
We show that the properties of Lagrangian mean curvature flow are a special case of a more general phenomenon, concerning couplings between geometric flows of the ambient space and of totally real submanifolds. Both flows are driven by ambient Ricci curvature or, in the non-Kähler case, by its analogues. To this end we…
We study the normal holonomy group, i.e. the holonomy group of the normal connection, of a CR-submanifold of a complex space form. We complete the local classification of normal holonomies for complex submanifolds. We show that the normal holonomy group of a coisotropic submanifold acts as the holonomy representation o…
This paper studies ruled real hypersurfaces in indefinite complex projective space.
problem Characterizing and classifying ruled real hypersurfaces in indefinite complex projective space.
method Introduced and studied ruled real hypersurfaces with maximal holomorphic distribution integrable and leaves totally geodesic holomorphic hyperplanes. Detailed shape operator computation and method of construction by gluing totally geodesic hyperplanes along a curve.
result Classification of all minimal ruled real hypersurfaces in terms of three main families of curves.
We obtain a basic inequality involving the Laplacian of the warping function and the squared mean curvature of any warped product isometrically immersed in a Riemannian manifold without assuming any restriction on the Riemann curvature tensor of the ambient manifold. Applying this general theory, we obtain basic inequa…
We study Kaehlerian manifolds with Norden metric g and develop the theory of their holomorphic hypersurfaces with constant totally real sectional curvatures. We prove a classification theorem for the holomorphic hypersurfaces of (R2n+2,g,J) with constant totally real sectional curvatures.
In trying to provide explicit deformations of quadrics the starting point of our investigation is to use Bianchi's link between real deformations of totally real regions of real paraboloids and various totally real forms of the sine-Gordon equation coupled with Bianchi's simple observation that the vacuum soliton of th…
This paper connects Salem numbers and totally real fields to Thurston's construction of pseudo-Anosov maps.
problem Understanding which algebraic units can be stretch factors of pseudo-Anosov maps.
method Using Thurston's construction, the paper shows that every Salem number and every totally real field can be represented as stretch factors of pseudo-Anosov maps.
result Every Salem number and every totally real field can be represented as stretch factors of pseudo-Anosov maps arising from Thurston's construction.
Classifies totally geodesic submanifolds in Hopf-Berger spheres.
problem Classifying totally geodesic submanifolds in Hopf-Berger spheres.
method Investigates Hopf-Berger spheres, a special family of homogeneous spaces diffeomorphic to spheres constructed via Hopf fibrations.
result Discovered intriguing examples of totally geodesic submanifolds, including isometric submanifolds of real projective spaces and non-congruent submanifolds.
Study shows finiteness of magnetic hypersurfaces on closed manifolds.
problem Understanding the finiteness of magnetic hypersurfaces on closed manifolds.
method Introduced a dynamical version of the second fundamental form to generalize a previous result.
result Real-analytic negatively s-curved magnetic systems on closed real-analytic manifolds have only finitely many closed totally s-magnetic hypersurfaces.
We use the solution space of a pair of ODEs of at least second order to construct a smooth surface in Euclidean space. We describe when this surface is a proper embedding which is geodesically complete with finite total Gauss curvature. If the associated roots of the ODEs are real and distinct, we give a universal uppe…
One purpose of this article is to establish a general method to determine stability of totally geodesic submanifolds of symmetric spaces. The method is used to determine the stability of the basic totally geodesic submanifolds M+,M− introduced and studied by Chen and Nagano in [Totally geodesic submanifolds of symm…
In this paper we show that all totally real superconformal minimal tori in CP2 correspond with doubly-periodic finite gap solutions of the Tzitzeica equation ωzz=e−2ω−eω Using the results on the Tzitzeica equation in integrable system theory, we describe explicitly all these tori by Prym-theta…
In this paper we study curvature properties of semi-symmetric type of totally umbilical radical transversal lightlike hypersurfaces (M,g) and (M,g) of a Kähler-Norden manifold (M,J,g,g) of constant totally real sectional curvatures ν and …
If (M,g) is a Riemannian manifold and x,y are points in M, then a subset P of M\{x,y} is said to be a blocking set for (x,y) if every geodesic from x to y passes through a point of P. If no pair (x,y) in M X M has a finite blocking set, then (M,g) is said to be totally insecure. We prove that there exist real analytic …
Complex hyperbolic manifolds with many totally geodesic submanifolds are arithmetic.
problem Characterizing arithmeticity of complex hyperbolic manifolds with certain submanifolds.
method Developing superrigidity theorems for complex hyperbolic lattices and proving nonexistence of certain maps.
result Finite volume complex hyperbolic n-manifolds containing infinitely many maximal totally geodesic submanifolds of dimension at least two are arithmetic.
Paper derives Chen's inequality for a specific type of submanifold in a generalized space form.
problem Deriving Chen's inequality for C-totally real submanifolds in a generalized (κ,μ)-space form.
method Using intrinsic and extrinsic invariants, the paper derives Chen's inequality involving scalar curvature, sectional curvatures, and squared mean curvature.
result Inequalities between squared mean curvature and Ricci curvature and between squared mean curvature and k-Ricci curvature are obtained.
We classify pseudo-Riemannian submersions with connected totally geodesic fibres from a real pseudo-hyperbolic space onto a pseudo-Riemannian manifold. Also, we obtain the classification of the pseudo-Riemannian submersions with (para-)complex connected totally geodesic fibres from a (para-)complex pseudo-hyperbolic sp…
We classify the polycyclic totally ordered simple dimension groups, i.e. dimension groups given by a dense embedding of n-dimensional lattice into the real line. Our method is based on the geometry of simple geodesics on the hyperbolic surface of genus greater or equal two. The main theorem says that isomorphism classe…
We prove that pseudo-holomorphic discs attached to a maximal totally real submanifold inherit their regularity from the regularity of the submanifold and of the almost complex structure. The proof is based on the computation of an explicit lower bound for the Kobayashi metric in almost complex manifolds, which also yie…
A real projective orbifold is an n-dimensional orbifold modeled on RPn with the group PGL(n+1,R). We concentrate on an orbifold that contains a compact codimension 0 submanifold whose complement is a union of neighborhoods of ends, diffeomorphic to closed (n−1)-dimensional orbifolds times …
In this paper we give a characterization of real hypersurfaces in noncompact complex two-plane Grassmannian SU2,m/S(U2Um), m≥2 with Reeb vector field ξ belonging to the maximal quaternionic subbundle Q. Then it becomes a tube over a totally real totally geodesic HHn, m=2n, in …