6 papers
Non-Hermitian Cooperation Induced Chern Insulator
Weiwei Zhu, Bingbing Wang, Mengxiang Xie +5
Conventional Chern insulators rely on breaking time-reversal symmetry via magnetic fields or synthetic gauge fields. Here we introduce a fundamentally different paradigm: a static…
Polynomial homological Dehn functions from non-proper actions
Roman Sauer, Jannis Weis
We establish a homological algebra framework for proving polynomiality of higher homological Dehn functions of groups. As an application, we show a combination theorem for polynomi…
An acylindrically hyperbolic group of non-uniform exponential growth
Roman Sauer, Eduard Schesler
We show the existence of an acylindrically hyperbolic group that has non-uniform exponential growth and Kazhdan's property . The group is constructed as a common quotient of a…
Non-uniform exponential growth and the decay of growth rates in growing dimensions
Roman Sauer, Eduard Schesler
We provide the first example of a finitely presented, and the first example of a simple, group of non-uniform exponential growth. The example is given by Thompson's group . Our…
The cheap embedding principle: Dynamical upper bounds for homology growth
Kevin Li, Clara Loeh, Marco Moraschini +2
We provide upper bounds for logarithmic torsion homology growth and Betti number growth of groups, phrased in the language of measured group theory.
The algebraic cheap rebuilding property
Kevin Li, Clara Loeh, Marco Moraschini +2
We present an axiomatic approach to combination theorems for various homological properties of groups and, more generally, of chain complexes. Examples of such properties include a…