scholarly journals Weak equivalence and the structures of cocycles of an ergodic automorphism

1991 ◽  
Vol 27 (4) ◽  
pp. 577-625 ◽  
Author(s):  
Sergey I. Bezuglyi ◽  
Valentin Ya. Golodets
2010 ◽  
Vol 17 (2) ◽  
pp. 229-240
Author(s):  
Marek Golasiński

Abstract An equivariant disconnected Sullivan–de Rham equivalence is developed using Kan's result on diagram categories. Given a finite Hamiltonian group G, let X be a G-simplicial set. It is shown that the associated system of algebras indexed by the category 𝒪(G) of a canonical orbit can be “approximated” (up to a weak equivalence) by such a system ℳ X with the properties required by nonequivariant minimal algebras.


2018 ◽  
Vol 861 (1) ◽  
pp. 66 ◽  
Author(s):  
Calvin Leung ◽  
Beili Hu ◽  
Sophia Harris ◽  
Amy Brown ◽  
Jason Gallicchio ◽  
...  

2000 ◽  
Vol 20 (2) ◽  
pp. 611-626 ◽  
Author(s):  
RICHARD SWANSON ◽  
HANS VOLKMER

Weak equivalence of primitive matrices is a known invariant arising naturally from the study of inverse limit spaces. Several new invariants for weak equivalence are described. It is proved that a positive dimension group isomorphism is a complete invariant for weak equivalence. For the transition matrices corresponding to periodic kneading sequences, the discriminant is proved to be an invariant when the characteristic polynomial is irreducible. The results have direct application to the topological classification of one-dimensional inverse limit spaces.


2018 ◽  
Vol 62 (2) ◽  
pp. 553-558
Author(s):  
Jonathan Ariel Barmak

AbstractIt is well known that if X is a CW-complex, then for every weak homotopy equivalence f : A → B, the map f* : [X, A] → [X, B] induced in homotopy classes is a bijection. In fact, up to homotopy equivalence, only CW-complexes have that property. Now, for which spaces X is f* : [B, X] → [A, X] a bijection for every weak equivalence f? This question was considered by J. Strom and T. Goodwillie. In this note we prove that a non-empty space inverts weak equivalences if and only if it is contractible.


2020 ◽  
Vol 499 (1) ◽  
pp. L53-L57
Author(s):  
Shu-Cheng Yang ◽  
Wen-Biao Han ◽  
Gang Wang

ABSTRACT The weak equivalence principle (WEP) is the cornerstone of gravitational theories. At the local scale, WEP has been tested to high accuracy by various experiments. On the intergalactic distance scale, WEP could be tested by comparing the arrival time of different messengers emitted from the same source. The gravitational time delay caused by massive galaxies is proportional to γ + 1, where the parameter γ is unity in general relativity. The values of γ for different massless particles should be different if WEP is violated, i.e. Δγ is used to indicate the deviation from WEP. So far, |Δγ| has been constrained with gamma-ray bursts, fast radio bursts, etc. Here, we report a new constraint of |Δγ| by using the gravitational wave data of binary black hole coalescences in the LIGO–Virgo catalogue GWTC-1. The best constraints imply that |Δγ| ≲ 10−15 at 90 per cent confidence level.


2000 ◽  
Vol 25 (6) ◽  
pp. 1245-1249 ◽  
Author(s):  
F.M. Huber ◽  
R.A. Lewis ◽  
E.W. Messerschmid ◽  
G.A. Smith

2014 ◽  
Vol 30 ◽  
pp. 1460267 ◽  
Author(s):  
C. S. Unnikrishnan

After a brief review of the evidence for the validity of the Weak Equivalence principle for anti-matter, I show that, contrary to general belief, the near equality of the Shapiro delay for photons, neutrinos and anti-neutrinos in the galactic gravitational potential is not a true test of the WEP for their intrinsic properties and quantum numbers due to the overwhelming contribution to the gravitational mass from the relativistic kinetic energy. Then I prove the remarkable result that particles that obey the Newtonian law of dynamics automatically respect the WEP due to the firm equivalence between the law of motion and the WEP in any relativistic scenario, through gravity of all the matter in the Universe. Thus a test of the validity of Newtons's law in any force field is a true test of the WEP and provides strong direct tests of WEP for anti-particles. This result opens up an entire new insight of conceptual and practical importance for the tests of WEP.


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