A tale of 2-groups: Dp(USp(2N)) theories

Massive Star Formation: A Tale of Two Theories

The physical mechanism that allows massive stars to form is a major unsolved problem in astrophysics. Stars with masses ∼ 20 M⊙ reach the main sequence while still embedded in their natal clouds, and the immense radiation output they generate once fusion begins can exert a force stronger than gravity on the dust and gas around them. They also produce huge Lyman continuum luminosities, which can...

HIV Rapid Diagnostic Test Inventories in Zambézia Province, Mozambique: A Tale of 2 Test Kits

Background The first pillar of the UNAIDS 90-90-90 goal seeks to accurately identify persons living with HIV (PLHIV), a process that is predicated on facilities having the necessary HIV tests available to perform the task. In many rural settings, the identification of PLHIV is accomplished through a two-step process involving the sequential use of 2 separate rapid diagnostic tests (RDTs)....

A tale of two groups: arithmetic groups and mapping class groups

In this chapter, we discuss similarities, differences and interaction between two natural and important classes of groups: arithmetic subgroups Γ of Lie groups G and mapping class groups Modg,n of surfaces of genus g with n punctures. We also mention similar properties and problems for related groups such as outer automorphism groups Out(Fn), Coxeter groups and hyperbolic groups. Since groups a...

Digital Necrosis: A Hoarder’s Tale

Definable Groups for Dependent and 2-dependent Theories

Let T be a (first order complete) dependent theory, C a κ̄-saturated model of T and G a definable subgroup which is abelian. Among subgroups of bounded index which are the union of < κ̄ type definable subsets there is a minimal one, i.e. their intersection has bounded index. See history in [Sh:876]. We then deal with definable groups for 2-dependent theories, a wider class of first order theories...