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A broader definition of generalized truncations of graphs is introduced followed by an exploration of some standard concepts and parameters with regard to generalized truncations.

Combinatorics · Mathematics 2020-07-10 Brian Alspach , Joshua B. Connor

We give a combinatorial description of closed curves on oriented surfaces in terms of certain permutations, called charts. We describe automorphisms of curves in terms of charts and compute the total number of curves counted with…

Geometric Topology · Mathematics 2007-05-23 Vladimir Turaev

We give necessary and sufficient topological conditions for a simple closed curve on a real rational surface to be approximable by smooth rational curves. We also study approximation by smooth rational curves with given complex…

Algebraic Geometry · Mathematics 2025-05-26 János Kollár , Frédéric Mangolte

We study the relative Hilbert scheme of a family of nodal (or smooth) curves, over a base of arbitrary dimension, via its (birational) cycle map, going to the relative symmetric product. We show the cycle map is the blowing up of the…

Algebraic Geometry · Mathematics 2008-04-01 Ziv Ran

The main result is a wall crossing formula for central projections defined on submanifolds of a real projective space. Our formula gives the jump of the degree of such a projection when the center of the projection varies. The fact that the…

Algebraic Geometry · Mathematics 2014-04-04 Christian Okonek , Andrei Teleman

Universal formulas for the boundary and crosscap coefficients are presented, which are valid for all symmetric simple current modifications of the charge conjugation invariant of any rational conformal field theory.

High Energy Physics - Theory · Physics 2008-11-26 J. Fuchs , L. R. Huiszoon , A. N. Schellekens , C. Schweigert , J. Walcher

We consider bicolored maps, i.e. graphs which are drawn on surfaces, and construct a bijection between (i) oriented maps with arbitary face structure, and (ii) (weighted) non-oriented maps with exactly one face. Above, each non-oriented map…

Combinatorics · Mathematics 2022-12-12 Agnieszka Czyżewska-Jankowska , Piotr Śniady

Fixed a point O on a non-singular surface S and a complete mO-primary ideal I in its local ring, the curves on the surface X obtained by blowing-up I are studied in terms of the base points of I. Criteria for the principality of these…

Algebraic Geometry · Mathematics 2007-05-23 Jesus Fernandez-Sanchez

We have presented computer simulations of conoscopic patterns occurring in optically uniaxial gyrotropic crystals in the vicinity of isotropic point for a number of sets of crystal parameters and orientations. The appearance of special…

Optics · Physics 2007-08-31 Yu. Vasylkiv , Yu. Nastishin , R. Vlokh

The concept of a visible point of a convex set relative to a given point is introduced. A number of basic properties of such visible point sets is developed. In particular, it is shown that this concept is useful in the study of best…

Functional Analysis · Mathematics 2012-11-07 Frank Deutsch , Hein Hundal , Ludmil Zikatanov

A systematic study of closed classical orbits of the hydrogen atom in crossed electric and magnetic fields is presented. We develop a local bifurcation theory for closed orbits which is analogous to the well-known bifurcation theory for…

Chaotic Dynamics · Physics 2009-11-07 T. Bartsch , J. Main , G. Wunner

In this paper, we will study the following pattern recognition problem: Every pattern is a 3-dimensional graph, its surface can be split up into some regions, every region is composed of the pixels with the approximately same colour value…

Neurons and Cognition · Quantitative Biology 2017-03-07 YongHong Chen

We propose a new cross-correlation method that can recognize independent realizations of the same type of stochastic processes and can be used as a new kind of pattern recognition tool in biometrics, sensing, forensic, security and image…

Data Analysis, Statistics and Probability · Physics 2007-05-23 Jong U. Kim , Laszlo B. Kish

2-stratifolds are a generalization of 2-manifolds in that there are disjoint simple closed curves where several sheets meet. They arise in the study of categorical invariants of 3-manifolds and may have applications to topological data…

Geometric Topology · Mathematics 2015-05-14 J. C. Gómez-Larrañaga , F. González-Acuña , Wolfgang Heil

We present a novel algorithm for deciding whether a given planar curve is an image of a given spatial curve, obtained by a central or a parallel projection with unknown parameters. A straightforward approach to this problem consists of…

Algebraic Geometry · Mathematics 2013-03-18 Joseph M. Burdis , Irina A. Kogan

We explore how the invariants $J^+$, $J^-$, $\mathcal{J}_1$ and $\mathcal{J}_2$ of immersions -- generic (at most double points and only transverse intersections) planar smooth closed curves with non-vanishing derivative -- change under…

Symplectic Geometry · Mathematics 2022-10-07 Alexander Mai

Oriented closed curves on an orientable surface with boundary are described up to continuous deformation by reduced cyclic words in the generators of the fundamental group and their inverses. By self-intersection number one means the…

Geometric Topology · Mathematics 2011-08-03 Moira Chas , Steven P. Lalley

This paper discusses consistent flag bicolorings of maps and maniplexes, in their own right and as generalizations of orientations and pseudo-orientations. Furthermore, a related doubling concept is introduced, and relationships between…

Combinatorics · Mathematics 2013-01-21 Hiroki Koike , Daniel Pellicer , Miguel Raggi , Steve Wilson

The bridge index and superbridge index of a knot are important invariants in knot theory. We define the bridge map of a knot conformation, which is closely related to these two invariants, and interpret it in terms of the tangent indicatrix…

Geometric Topology · Mathematics 2012-05-24 Colin Adams , Dan Collins , Katherine Hawkins , Charmaine Sia , Robert Silversmith , Bena Tshishiku

Point-determining graphs are graphs in which no two vertices have the same neighborhoods, co-point-determining graphs are those whose complements are point-determining, and bi-point-determining graphs are those both point-determining and…

Combinatorics · Mathematics 2009-11-10 Ira Gessel , Ji Li