Envelopes of certain solvable groups

A discrete subgroup $\Gamma$ of a locally compact group $H$ is called a uniform lattice if the quotient $H/\Gamma$ is compact. Such an $H$ is called an envelope of $\Gamma$. In this paper we study the problem of classifying envelopes of various solvable groups including the solvable Baumslag-Solitar groups, lamplighter groups and certain abelian-by-cyclic groups. Our techniques are geometric and quasi-isometric in nature. In particular we show that for every $\Gamma$ we consider there is a finite family of preferred model spaces $X$ such that, up to compact groups, $H$ is a cocompact subgroup of $Isom(X)$.Comment: To appear in Commentarii Mathematici Helvetici, 30 page

Quasisymmetric maps of boundaries of amenable hyperbolic groups

In this paper we show that if $Y=N \times \mathbb{Q}_m$ is a metric space where $N$ is a Carnot group endowed with the Carnot-Caratheodory metric then any quasisymmetric map of $Y$ is actually bilipschitz. The key observation is that $Y$ is the parabolic visual boundary of a mixed type locally compact amenable hyperbolic group. The same results also hold for a larger class of nilpotent Lie groups $N$. As part of the proof we also obtain partial quasi-isometric rigidity results for mixed type locally compact amenable hyperbolic groups. Finally we prove a rigidity result for uniform subgroups of bilipschitz maps of $Y$ in the case of $N= \mathbb{R}^n$.Comment: To appear in the Indiana University Mathematics Journal, 19 page

Consultants in Academic Libraries: Challenging, Renewing, and Extending the Dialogue

There is a trend in academic libraries to hire consultants for internal crises, change management projects, strategic planning processes, outcomes assessment, evidence-based decision making, information literacy instruction, and more. Although we hear informally about the use of consultants in academic libraries, the practice has gone unexamined. We employ a historical and linguistic analysis of consultants in academic libraries, using a critical framework for this research. A critical perspective provides a structure to discuss issues that librarians may not have been able to previously fit into library practice dialogue. A chronological history of consulting in libraries acts as our literature review. This review, along with a targeted examination of library and information science resources, is used to guide two lines of linguistic analysis. The first provides a critique of the core tenets used to define and characterize library consultants, namely, the claim that consultants are unbiased professionals who bring “expertise” and “fresh” ideas to libraries. The second analysis investigates the rhetorical strategies used in existing texts: polarizing language, straw man reasoning, and figurative and indirect language. The discussion section unpacks these linguistic strategies, reflects on what is missing from the texts, and considers how knowledge and power are exerted through language, making connections to the broader context of neoliberalism