The quantitative coarse Baum–Connes conjecture with coefficients

Let XX be a proper metric space, let NXN_X be a locally finite net in XX, and write Pk=Pk(NX)P_k=P_k(N_X) for its Rips complex. For kkk\leq k', let QIA(k,k,ε,r)QI_A(k,k',\varepsilon,r) and QSA(k,k,ε,ε,r,r)QS_A(k,k',\varepsilon,\varepsilon',r,r') be the quantitative statements defined using the localization and quantitative Roe algebras, with 0<εε<1/40<\varepsilon\leq\varepsilon'<1/4 and r+1rr+1\leq r'.

Quantitative coarse Baum–Connes conjecture with coefficients. For every kNk\in\mathbb{N}, there exists 0<ε<1/40<\varepsilon<1/4 such that, for every r>0r>0, there exists kkk'\geq k for which QIA(k,k,ε,r)QI_A(k,k',\varepsilon,r) holds for XX; and there exists kkk'\geq k, rr+1r'\geq r+1, and 1/4>εε1/4>\varepsilon'\geq\varepsilon for which QSA(k,k,ε,ε,r,r)QS_A(k,k',\varepsilon,\varepsilon',r,r') holds for XX.

This quantitative refinement of the coarse Baum–Connes conjecture is the main notion introduced in the paper. The source proves that the ordinary coarse Baum–Connes conjecture with coefficients implies it, yielding many examples, but does not claim that the conjecture is resolved in general.

Sources & referencesView supporting material

Primary source

Jianguo Zhang, “On the quantitative coarse Baum-Connes conjecture with coefficients”, arXiv:2410.11929 (2024).

Progress summary

Never refreshed

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

Solutions 0

No solutions have been posted yet.