Zobrazeno 1 - 10
of 878
pro vyhledávání: '"Ramsey, Christopher"'
Given an infinite word ${\bf w}$ on a finite alphabet, an immediate question arises:~can we understand the frequency of letters in ${\bf w}$\,? For words that are the fixed points of substitutions, the answer to this question is often `yes' -- the de
Externí odkaz:
http://arxiv.org/abs/2410.12173
In this paper, we show that the diffraction of the primes is absolutely continuous, showing no bright spots (Bragg peaks). We introduce the notion of counting diffraction, extending the classical notion of (density) diffraction to sets of density zer
Externí odkaz:
http://arxiv.org/abs/2406.13687
Autor:
de Beaudrap, Niel, Ramsey, Christopher
This paper studies the diameter of the numerical range of bounded operators on Hilbert space and the induced seminorm, called the numerical diameter, on bounded linear maps between operator systems which is sensible in the case of unital maps and the
Externí odkaz:
http://arxiv.org/abs/2402.06791
In this paper, we show that the semi-Dirichlet C*-covers of a semi-Dirichlet operator algebra form a complete lattice, establishing that there is a maximal semi-Dirichlet C*-cover. Given an operator algebra dynamical system we prove a dilation theory
Externí odkaz:
http://arxiv.org/abs/2309.16130
We prove that a substitution is aperiodic if and only if some of its associated generating functions are transcendental. These generating functions have a recursive structure arising from the substitution which we use to study their roots in the case
Externí odkaz:
http://arxiv.org/abs/2309.16100
Autor:
Humeniuk, Adam, Ramsey, Christopher
In this paper it is shown that the lattice of C$^*$-covers of an operator algebra does not contain enough information to distinguish operator algebras up to completely isometric isomorphism. In addition, four natural equivalences of the lattice of C$
Externí odkaz:
http://arxiv.org/abs/2304.02783
We find explicit optimal vertex, edge and face coulourings for the chair tiling, the Ammann--Beenker tiling, the rational pinwheel tiling and the pinwheel tiling.
Comment: 25 pages
Comment: 25 pages
Externí odkaz:
http://arxiv.org/abs/2209.06364
Autor:
Gawlak, Dylan, Ramsey, Christopher
In this paper we look at symbolic substitutions and their relationship to Bratteli diagrams and their associated operator algebras. In particular, we consider the equivalence relation on substitutions induced by telescope equivalence of Bratteli diag
Externí odkaz:
http://arxiv.org/abs/2110.13256
Autor:
Katsoulis, Elias, Ramsey, Christopher
We resolve the isomorphism problem for tensor algebras of unital multivariable dynamical systems. Specifically we show that unitary equivalence after a conjugation for multivariable dynamical systems is a complete invariant for complete isometric iso
Externí odkaz:
http://arxiv.org/abs/2101.07834
Autor:
Ramsey, Christopher, Reeves, Adam
We define a p-norm in the context of quantum random variables, measurable operator-valued functions with respect to a positive operator-valued measure. This norm leads to a operator-valued L^p space that is shown to be complete. Various other norm ca
Externí odkaz:
http://arxiv.org/abs/2008.08569