Results 1 to 10 of about 8,270,142 (310)

Computing characteristic classes of projective schemes [PDF]

Journal of Symbolic Computation, 2003
We discuss an algorithm computing the push-forward to projective space of several classes associated to a (possibly singular, reducible, nonreduced) projective scheme. For example, the algorithm yields the topological Euler characteristic of the support of a projective scheme $S$, given the homogeneous ideal of $S$.
P. Aluffi
semanticscholar   +6 more sources

Bundles over Quantum RealWeighted Projective Spaces

Axioms, 2012
The algebraic approach to bundles in non-commutative geometry and the definition of quantum real weighted projective spaces are reviewed. Principal U(1)-bundles over quantum real weighted projective spaces are constructed.
Tomasz Brzeziński, Simon A. Fairfax
doaj   +4 more sources

Projective duality and a Chern-Mather involution [PDF]

, 2016
We observe that linear relations among Chern-Mather classes of projective varieties are preserved by projective duality. We deduce the existence of an explicit involution on a part of the Chow group of projective space, encoding the effect of duality on ...
Aluffi, Paolo
core   +2 more sources

Two new classes of projective two-weight linear codes [PDF]

Finite Fields Their Appl., 2021
In this paper, for an odd prime $p$, several classes of two-weight linear codes over the finite field $\mathbb{F}_p$ are constructed from the defining sets, and then their complete weight distributions are determined by employing character sums.
Canze Zhu, Qunying Liao
semanticscholar   +1 more source

A Model in Which Well-Orderings of the Reals First Appear at a Given Projective Level, Part III—The Case of Second-Order PA

Mathematics, 2023
A model of set theory ZFC is defined in our recent research, in which, for a given n≥3, (An) there exists a good lightface Δn1 well-ordering of the reals, but (Bn) no well-orderings of the reals (not necessarily good) exist in the previous class Δn−11 ...
Vladimir Kanovei, Vassily Lyubetsky
doaj   +1 more source

Projective classes as images of accessible functors

Journal of Logic and Computation, 2022
We are dealing with projective classes (in short $\textrm {PC}$) over first-order vocabularies with no restrictions on the (possibly infinite) arities of relation or operation symbols.
F. Wehrung
semanticscholar   +1 more source

A Model in Which Well-Orderings of the Reals First Appear at a Given Projective Level, Part II

Mathematics, 2023
We consider the problem of the existence of well-orderings of the reals, definable at a certain level of the projective hierarchy. This research is motivated by the modern development of descriptive set theory.
Vladimir Kanovei, Vassily Lyubetsky
doaj   +1 more source

Composition properties of projective homotopy classes [PDF]

Pacific Journal of Mathematics, 1977
Feder, S., Gitler, S., Lam, K. Y.
openaire   +4 more sources

On the Significance of Parameters in the Choice and Collection Schemata in the 2nd Order Peano Arithmetic

Mathematics, 2023
We make use of generalized iterations of the Sacks forcing to define cardinal-preserving generic extensions of the constructible universe L in which the axioms of ZF hold and in addition either (1) the parameter-free countable axiom of choice ACω* fails,
Vladimir Kanovei, Vassily Lyubetsky
doaj   +1 more source

Class Nearly kahler Manifold of W – Projective Curvature Tensor

Tikrit Journal of Pure Science, 2023
The current study deals with new three classes of the  manifold of w – projective curvature tensor. The aim of this paper to calculate differential - geometrical and topological properties closest for new classes , and , through it ,an equivalence ...
Ali Khalaf Ali, A. A.Shihab
doaj   +1 more source