Results 51 to 60 of about 9,476 (202)
Non-existence of quasi-symmetric designs having certain pseudo-geometric block graphs
AKCE International Journal of Graphs and CombinatoricsThe block graph of a quasi-symmetric design is strongly regular. It is a challenging problem to decide which strongly regular graphs are block graphs of quasi-symmetric designs.
Kusum S. Rajbhar, Rajendra M. Pawale
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Rational points on even‐dimensional Fermat cubics
Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.Abstract We show that even‐dimensional Fermat cubic hypersurfaces are rational over any field of characteristic not equal to three, by constructing explicit rational parameterizations with polynomials of low degree. As a byproduct of our rationality constructions, we obtain estimates for the number of their rational points over a number field and ...
Alex Massarenti
wiley +1 more source
Rational rolling ball blending of natural quadrics
Mathematical Modelling and Analysis, 2000 We construct a blending surface of two natural quadrics using rational variable rolling ball approach, i.e. as a canal surface with a rational spine curve and a rational radius. All general positions of the given quadric surfaces are considered.
K. Karčiauskas, R. Krasauskas
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Noncommutative quadric surfaces
Journal of Noncommutative Geometry, 2013 The 4-dimensional Sklyanin algebra is the homogeneous coordinate ring of a noncommutative analogue of projective 3-space. The degree-two component of the algebra contains a 2-dimensional subspace of central elements. The zero loci of those central elements, except 0, form a pencil of noncommutative quadric surfaces.
Van Den Bergh, Michel, Smith, Paul
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Intersections of three quadrics in $\mathbb{P}^7$ [PDF]
, 2017 We study rationality properties of smooth complete intersections of three quadrics in $\mathbb{P}^7$. We exhibit a smooth family of such intersections with both rational and non-rational fibers.
B. Hassett, Alena Pirutka, Y. Tschinkel
semanticscholar +1 more source
Osculating geometry and higher‐order distance Loci
Journal of the London Mathematical Society, Volume 113, Issue 3, March 2026.Abstract We discuss the problem of optimizing the distance function from a given point, subject to polynomial constraints. A key algebraic invariant that governs its complexity is the Euclidean distance degree, which pertains to first‐order tangency. We focus on the data locus of points possessing at least one critical point of the distance function ...
Sandra Di Rocco +2 more
wiley +1 more source
IET Microwaves, Antennas & Propagation, 2023 This study proposes an analytical formulation in complex coordinates to synthesise three‐dimensional single‐shell dielectric lens surfaces. An exact formulation based on geometrical optics is developed, and the synthesis problem is modelled as a non ...
Aline Rocha deAssis +2 more
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Double quadrics with large automorphism groups [PDF]
, 2016 We classify nodal Fano threefolds that are double covers of smooth quadrics branched over intersections with quartics and are acted on by finite simple non-abelian groups. We also study their rationality.
V. Przyjalkowski, C. Shramov
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The motive of the Hilbert scheme of points in all dimensions
Proceedings of the London Mathematical Society, Volume 132, Issue 3, March 2026.Abstract We prove a closed formula for the generating series Zd(t)$\mathsf {Z}_d(t)$ of the motives [Hilbd(An)0]$[\operatorname{Hilb}^d({\mathbb {A}}^n)_0]$ in K0(VarC)$K_0(\operatorname{Var}_{{\mathbb {C}}})$ of punctual Hilbert schemes, summing over n$n$, for fixed d>0$d>0$.
Michele Graffeo +3 more
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Application of an RBF blending interpolation method to problems with shocks
Computer Assisted Methods in Engineering and Science, 2017 Radial basis functions (RBF) have become an area of research in recent years, especially in the use of solving partial differential equations (PDE). Radial basis functions have an impressive capability in interpolating scattered data, even for data with
Michael Harris +2 more
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