Let n = (n1, . . . , nr). The quotient space Pn := S n1× · · ·×Snr/(x ∼ −x) is what we call a projective product space. We determine the integral cohomology ring H∗(Pn) and the action of the Steenrod algebra on H∗(Pn;Z2). We give a splitting of ΣPn in terms of stunted real projective spaces, and determine when Si is a product factor of Pn. We relate the immersion dimension and span of Pn to the...

Let n = (n1, . . . , nr). The quotient space Pn := Sn1× · · ·×Snr/(x ∼ −x) is what we call a projective product space. We determine the integral cohomology ring H∗(Pn) and the action of the Steenrod algebra on H∗(Pn;Z2). We give a splitting of ΣPn in terms of stunted real projective spaces, and determine when Si is a product factor of Pn. We relate the immersion dimension and span of Pn to the ...

Let S be a smooth complex projective surface and Hilbn(S) the Hilbert scheme of all length n zero-dimensional subschemes of S. It is known (cf. [Fo]) that Hilbn(S) is a smooth projective variety of dimension 2n. The structure of the cohomology ring ofHilbn(S) for a fixed n is rather difficult to understand. However, when we consider the direct sum ⊕ n≥0 H ∗(Hilbn(S)) (all cohomology in this pap...

Let $R$ be a commutative Noetherian ring with non-zero identity and $fa$ an ideal of $R$. Let $M$ be a finite $R$--module of finite projective dimension and $N$ an arbitrary finite $R$--module. We characterize the membership of the generalized local cohomology modules $lc^{i}_{fa}(M,N)$ in certain Serre subcategories of the category of modules from upper bounds. We define and study the properti...

Evaluators and researchers often have to deal with situations in which conventional research tools are impossible to use, either because of the characteristics of a population or unclear research variables. This paper presents a technique that succeeds in overcoming this kind of problem--a projective technique, but one that differs from the usual approach to projective techniques. The approach ...

During recent years, several studies have revealed that human-dog relationships are based on a well-established and complex bond. There is now evidence suggesting that the dog-human affectional bond can be characterized as an "attachment". The present study investigated possible association between the owners' attachment profile assessed throughout a new semi-projective test (the 9 Attachment P...

We introduce the notion of the projective linking number LinkP(Γ, Z) of a compact oriented real submanifold Γ of dimension 2p − 1 in complex projective n-space P with an algebraic subvariety Z ⊂ P − Γ of codimension p. This notion is related to projective winding numbers and quasi-plurisubharmonic functions, and it is generalized to any projective manifold X . It is shown that a basic conjectur...

Introduction. If P is a ring and M a left P-module, then homological algebra attaches three dimensions to M, projective, weak, and injective(1)By taking the supremum of one of these dimensions as M ranges over all left P-modules, one obtains one of the left "global" dimensions of R. Auslander and Buchsbaum [3] and, subsequently, Serre [14], found it relevant and fruitful, in the study of commut...

Let S be a polynomial algebra over field. If I is the edge ideal of perfect semiregular tree, then we give precise formulas for values depth, Stanley projective dimension, regularity and Krull dimension S/I.

Definition 1.1. Let L be a line bundle on a normal, irreducible, projective variety. Then the Iitaka dimension of L is defined to be the maximum dimension of the image of πm for m ⊕ N(X, L) provided N(X, L) ∈= 0. If N(X, L) = 0, then the Iitaka dimension of L is defined to be −→. When X is smooth, the Kodaira dimension of X is defined to be the Iitaka dimension of its canonical bundle KX . If X...