On Neutrinos and Fermionic Mass Patterns

Recent data on neutrino mass differences are consistent with a hierarchical neutrino mass structure strikingly similar to what is observed for the other fermionic masses.Comment: 8pages, 2figure

Twenty years of punishment (and democracy) in South Africa: The pitfalls of governing crime through the community

This article examines how the ideology of ‘community’ is deployed to  govern crime in South Africa, both by marginalised black communities and by the government. Although the turn to ‘community’ started under theNational Party government in the late 1970s, there is no doubt that as a site, technology, discourse, ideology and form of governance, ‘community’ has become entrenched in the post-1994 era. Utilising empirical data drawn from ethnographic research on vigilantism in Khayelitsha, as well as archival materials in respect of ANC policies and practices before it became the governing party, I argue that rallying ‘communities’ around crime combatting has the potential to unleash violent technologies in the quest for ‘ethics’ and ‘morality’. When community members unite against an outsider they are bonded for an intense moment in a way that masks thevery real problems that tear the community apart. Because violent  punishment is one of the consequences of the state’s turn towards   democratic localism, we should question the way in which the ‘community’ is deployed as a tool of crime prevention, and subject it to rigorous scrutin

Constructing Dirac linear fermions in terms of non-linear Heisenberg spinors

We show that the massive (or massless) neutrinos can be described as special states of Heisenberg nonlinear spinors. As a by-product of this decomposition a particularly attractive consequence appears: the possibility of relating the existence of only three species of mass-less neutrinos to such internal non-linear structure. At the same time it allows the possibility that neutrino oscillation can occurs even for massless neutrinos

Symmetries, Large Leptonic Mixing and a Fourth Generation

We show that large leptonic mixing occurs most naturally in the framework of the Sandard Model just by adding a fourth generation. One can then construct a small $Z_4$ discrete symmetry, instead of the large $S_{4L}\times S_{4R}$, which requires that the neutrino as well as the charged lepton mass matrices be proportional to a $4\times 4$ democratic mass matrix, where all entries are equal to unity. Without considering the see-saw mechanism, or other more elaborate extensions of the SM, and contrary to the case with only 3 generations, large leptonic mixing is obtained when the symmetry is broken.Comment: 6 pages, ReVTeX, no figure

A robust subspace based approach to feedforward control of broadband disturbances on a six-degrees-of-freedom vibration isolation set-up

The contribution of this paper is twofold. First, the paper introduces a novel hybrid vibration isolation approach which uses a combination of passive and active vibration control techniques to provide additional design freedom. The approach can be used to meet higher design requirements with respect to vibration isolation. To illustrate the feasibility of the approach, a stiff hybrid sixdegrees-of-freedom vibration isolation set-up will be presented. The objective of the set-up is to investigate if the receiver structure can be isolated from the source structure by six hybrid vibration isolation mounts, such that disturbances induced by the source structure are isolated from the receiver structure. Vibration isolation is established by minimizing signals from six acceleration sensor outputs and by steering six piezo-electric actuator inputs. Our second contribution is that a state space based fixed gain H2 controller is designed, implemented and validated. Real-time broadband feedforward control results are presented (between 0 - 1 kHz) which show that an average reduction of 8.0 dB is achieved in the error sensor outputs in real-time

Civic‐led banishment in South Africa: punishment, authority, and spatialised precarity

Civic-led banishment, a fundamentally spatial punishment, is an understudied phenomenon in South Africa and beyond. We define it as “a punitive spatial practice, enacted by non-state actors in response to alleged criminality or deviance, which attempts varying degrees of socio-spatial expulsion over time”. This definition lays the framework for a socio-spatial analysis of punishment, and yields insights into the exercise of socio-spatial control in public and private space. We emphasise the specific challenges associated with banishment, together with the relationship between space, punishment, public authority, and sovereignty. We demonstrate how “negotiations” around banishment trade off two forms of intersecting precarity: those faced by residents in informal settlements and the potential precarity of public authorities. Finally, we argue that an exploration of all forms of punishment through the lens of socio-spatial expulsion enables us to tap into conversations around penal abolitionism