In this paper, we give new constructions of disjoint difference families from Galois rings. The constructions are based on choosing cosets of the unit group of a subring in the Galois ring GR(p2, p2s). Two infinite families of disjoint difference families are obtained from the Galois rings GR(p2, p4n) and GR(22, 22s).

Abstract We consider Calabi–Yau n -folds X arising from certain hyperplane arrangements. Using Fu–Vial’s theory of distinguished cycles for varieties with motive abelian type, we show that the subring Chow ring generated by divisors, Chern classes and intersections subvarieties positive codimension injects into cohomology. also prove Voisin’s conjecture , Voevodsky’s smash-nilpotence odd-dimens...

We describe the Chow ring with rational coefficients of M0,1(P , d) as the subring of invariants of a ring B(M0,1(P , d);Q), relative to the action of the group of symmetries Sd. We compute B(M0,1(P , d);Q) by following a sequence of intermediate spaces for M0,1(P , d).

Let ĩ be a subring. We wish to extend the results of [9, 14] to hyper-bijective primes. We show that there exists a trivial almost Noether, everywhere anti-Fourier, sub-discretely super-Gauss–Hadamard line. The work in [34] did not consider the combinatorially parabolic case. This leaves open the question of structure.

Let yC be an almost surely compact, almost everywhere super-embedded system. The goal of the present article is to examine maximal isometries. We show that every injective subring is contravariant. It was Kovalevskaya who first asked whether countable homomorphisms can be extended. A useful survey of the subject can be found in [6].

We discuss controllability of systems that are initially given by boundary coupled p.d.e. of second order. Those systems may be described by modules over a certain subring R of the ring M0 of Mikusiński-Operators with compact support. We show that the ring R is a Bézout domain. This property is utilized in order to derive algebraic and trajectory related controllability results.

In this paper we prove, without assuming Schanuel’s conjecture, that the E-subring generated by a real number not definable without parameters in the real exponential field is freely generated. We also obtain a similar result for the complex exponential field.

We study a class of algebras associated with linear spaces and its relations with polymatroids and integral posets, i.e. posets supporting homogeneous ASL. We prove that the base ring of a transversal polymatroid is Koszul and describe a new class of integral posets. As a corollary we obtain that every Veronese subring of a polynomial ring is an ASL.

Let R be any subring of the reals. We present a generalization of linear systems on graphs where divisors are R-valued functions on the set of vertices and graph edges are permitted to have nonnegative weights in R. Using this generalization, we provide an independent proof of a Riemann-Roch formula, which implies the Riemann-Roch formula of Baker and Norine.

A unitary commutative ring of characteristic 3 and 3-potent is called a 3-ring. We prove that every polynomial of a 3-ring is uniquely determined by its restriction on the subring {0, 1, 2} (the Verification Theorem). Then we establish an isomorphism between the category of 3-rings and the category of Post algebras of order 3.