scholarly journals Sets of lengths in atomic unit-cancellative finitely presented monoids

2018 ◽  
Vol 151 (2) ◽  
pp. 171-187 ◽  
Author(s):  
Alfred Geroldinger ◽  
Emil Daniel Schwab
2018 ◽  
Vol 17 (01) ◽  
pp. 1850014 ◽  
Author(s):  
Jian Wang ◽  
Yunxia Li ◽  
Jiangsheng Hu

In this paper, we introduce and study left (right) [Formula: see text]-semihereditary rings over any associative ring, and these rings are exactly [Formula: see text]-semihereditary rings defined by Mahdou and Tamekkante provided that [Formula: see text] is a commutative ring. Some new characterizations of left [Formula: see text]-semihereditary rings are given. Applications go in three directions. The first is to give a sufficient condition when a finitely presented right [Formula: see text]-module is Gorenstein flat if and only if it is Gorenstein projective provided that [Formula: see text] is left coherent. The second is to investigate the relationships between Gorenstein flat modules and direct limits of finitely presented Gorenstein projective modules. The third is to obtain some new characterizations of semihereditary rings, [Formula: see text]-[Formula: see text] rings and [Formula: see text] rings.


1968 ◽  
Vol 33 (2) ◽  
pp. 296-297
Author(s):  
J. C. Shepherdson

1998 ◽  
Vol 58 (3) ◽  
pp. 435-444 ◽  
Author(s):  
Inkang Kim

In this paper we show that the space of irreducible representations from a finitely presented group into the group of isometries of a rank one symmetric space of non-compact type, embeds into ℝn for some n, where the coordinates are the translation lengths of isometries in the representation. The ingredients of the proof consist of the two facts that the representation is determined by its marked length spectrum and that the nested sequence of algebraic subvarieties is stabilised at a finite step by the Noetherian property of the polynomial ring. As a minor application, we use this fact to simplify McMullen's proof about the exponential algebraic convergence of Thurston's double limit to the geometrically infinite manifold in the space of discrete faithful representations of π1(S) in Iso+.


2012 ◽  
Vol 216 (5) ◽  
pp. 1033-1039 ◽  
Author(s):  
Ferran Cedó ◽  
Eric Jespers ◽  
Georg Klein
Keyword(s):  

2012 ◽  
Vol 14 (03) ◽  
pp. 1250017 ◽  
Author(s):  
LEONARDO CABRER ◽  
DANIELE MUNDICI

An ℓ-groupG is an abelian group equipped with a translation invariant lattice-order. Baker and Beynon proved that G is finitely generated projective if and only if it is finitely presented. A unital ℓ-group is an ℓ-group G with a distinguished order unit, i.e. an element 0 ≤ u ∈ G whose positive integer multiples eventually dominate every element of G. Unital ℓ-homomorphisms between unital ℓ-groups are group homomorphisms that also preserve the order unit and the lattice structure. A unital ℓ-group (G, u) is projective if whenever ψ : (A, a) → (B, b) is a surjective unital ℓ-homomorphism and ϕ : (G, u) → (B, b) is a unital ℓ-homomorphism, there is a unital ℓ-homomorphism θ : (G, u) → (A, a) such that ϕ = ψ ◦ θ. While every finitely generated projective unital ℓ-group is finitely presented, the converse does not hold in general. Classical algebraic topology (à la Whitehead) is combined in this paper with the Włodarczyk–Morelli solution of the weak Oda conjecture for toric varieties, to describe finitely generated projective unital ℓ-groups.


2017 ◽  
Vol 9 (5) ◽  
pp. 42
Author(s):  
Ogaba Philip Obande

The fundamental physical constants (FCs) are parametrized. The results reveal that: 1) FCs are field coupling constants. With the exception of ratio of identities such as μ = mp/me, there are no dimensionless constants – all FCs, including Alpha and pi, are dimensional. 2) The constant k = 1.6022 x 10-19 implicates: i) atomic unit of torque, it causes matter’s intrinsic rotation on all (atomic to cosmic) scales; ii) motion of unrestricted bodies through free space and random thermal (Brownian) motion in condensed matter; iii) superluminal space expansion, i.e., Hubble effect is not an acceleration but tangential velocity (pi c) of free space; and iv) common parametric definition of radioactivity and stellar explosion/supernova. 3) Newtonian gravitation comprises two potentials, a spherical pneumatic torque field G1 acts to inflate the gravitational envelope and a combination of force fields G2 impacts an acute hydrostatic pressure on the individual and common envelopes of the gravitating bodies; the two contrary force fields function to create a coherent rigid system in dynamic equilibrium. 4) The bosonic unit mass gravitational acceleration constant, gw = 7.9433 x 1059 m s-2 kg-1 is associated with the strong nuclear force (SNF), it binds matter on all (atomic to cosmic) scales. 5) Although the classical electron radius (CER) formulation re = e2/mec2 yields correct value, it is nonetheless fortuitous as me deviates from the theoretical value by twenty orders of magnitude and theory does not link spatial dimension to electrostatics charge quantum. 6) Successful evaluation of re by three alternative methods implies that an attempt to relegate the CER as currently obtains in the Standard Model seeks to re-engineer reality. 7) Electron bosonic radius identifies with the astronomical unit, it accounts for “spooky” action at a distance and “entanglement” effects. 8) Planck length fails to relate to atomic spatial dimension indicating that Planck space does not refer to the atom. 9) Electric, magnetic and gravitational effects are all motivated by torque but its magnitude differs according to the order: electrical (N m) > magnetic (N m)0.75 > gravitational (N m)0.25. It is submitted that even if the atom degraded with cosmological epoch, values of the FCs would remain fixed because they are parametric relative quantities.


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