Invariant-measure variational principle for r-neutralized topological entropy

From papers

Let (X,d)(X,d) be a compact metric space, let f:XXf:X\to X be a homeomorphism, and let M(f,X)\mathcal{M}(f,X) be the invariant Borel probability measures for ff. For r>0r>0, define the rr-neutralized topological entropy and lower rr-neutralized topological entropy by

hdr(f):=limn1nlogSd(f,n,enr),hdr(f):=limn1nlogSd(f,n,enr).h_{d}^r(f):=\varlimsup_{n \to \infty} \frac{1}{n}\log S_{d}(f,n,e^{-nr}),\qquad \underline{h}_{d}^r(f):=\varliminf_{n \to \infty}\frac{1}{n}\log S_{d}(f,n,e^{-nr}).

Here Sd(f,n,enr)S_d(f,n,e^{-nr}) is the minimal cardinality of an (n,enr)(n,e^{-nr})-spanning set. Invariant-measure variational principle. For every r>0r>0,

hdr(f)=sup{hν,dr(f):μM(f,X)},hdr(f)=sup{hν,dr(f):μM(f,X)}.h_{d}^r(f)=\sup\{h_{\nu,d}^r(f):\mu\in\mathcal{M}(f,X)\},\qquad \underline{h}_{d}^r(f)=\sup\{\underline{h}_{\nu,d}^r(f):\mu\in\mathcal{M}(f,X)\}.

This is proposed as an analogue of the classical variational principle, replacing the supremum over Borel probability measures by one over invariant measures. The claim is stated for homeomorphisms and both upper and lower rr-neutralized entropies; the source provides no resolution.

Progress summary

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Sources & referencesView supporting material

Primary source

Changguang Dong and Qiujie Qiao, “On r-Neutralized Entropy: Entropy Formula and Existence of Measures Attaining the Supremum”, arXiv:2408.02397 (2024).

Solutions 0

No solutions have been posted yet.