Higher-dimensional routes to the Standard Model bosons

In the old spirit of Kaluza-Klein, we consider a spacetime of the form $P = M_4 \times K$, where $K$ is the Lie group $\mathrm{SU}(3)$ equipped with a left-invariant metric that is not fully right-invariant. This metric has a ${\rm U}(1) \times \mathrm{SU}(3)$ isometry group, corresponding to the massless gauge bosons, and depends on a parameter $\phi$ with values in a subspace of $\mathfrak{su}(3)$ isomorphic to $\mathbb{C}^2$. It is shown that the classical Einstein-Hilbert Lagrangian density $R_P - 2 \Lambda$ on the higher-dimensional manifold $P$, after integration over $K$, encodes not only the Yang-Mills terms of the Standard Model over $M_4$, as in the usual Kaluza-Klein calculation, but also a kinetic term $|{\mathrm d}^A \phi|^2$ identical to the covariant derivative of the Higgs field. For $\Lambda$ in an appropriate range, it also encodes a potential $V(| \phi|^2)$ having absolute minima with $|\phi_0|^2 \neq 0$, thereby inducing mass terms for the remaining gauge bosons. The classical masses of the resulting Higgs-like and gauge bosons are explicitly calculated as functions of the vacuum value $|\phi_0|^2$ in the simplest version of the model. In more general versions, the classical values of the strong and electroweak gauge coupling constants are given as functions of the parameters of the left-invariant metric on $K$.Comment: 69 pages, 6 figures; v2: small correction

Internal symmetries in Kaluza-Klein models

The usual approach to Kaluza-Klein considers a spacetime of the form $M_4 \times K$, where the internal space is a compact manifold equipped with a vacuum metric, denoted $g_K^0$, whose isometry group becomes the gauge group in four dimensions. In these notes we discuss a variant approach where part of the gauge group does not come from full isometries of $g_K^0$, but instead comes from weaker internal symmetries that only preserve the Einstein-Hilbert action on $K$. Then the weaker symmetries are spontaneously broken by the choice of vacuum metric and generate massive gauge bosons within the Kaluza-Klein framework, with no need to introduce ad hoc Higgs fields. Using the language of Riemannian submersions, it is shown that a gauge boson's classical mass depends on the Lie derivative of $g_K^0$ along the associated internal symmetry. The presence of gauge fields that are not associated with exact isometries of $g_K^0$ may help to circumvent certain no-go arguments against the existence of chiral fermions in Kaluza-Klein theories. In parallel, we also discuss the traditional assumption that the Kaluza-Klein vacuum is represented by a product Einstein metric. This should not be true when that metric is unstable. In fact, the unravelling of the Einstein metric along unstable perturbations may be a desirable feature of the model. It allows certain components of the metric to change length scale and become compatible with a small cosmological constant. In the case of the Lie group $K=SU(3)$, the unravelling of the bi-invariant metric along an unstable perturbation also breaks the isometry group from $(SU(3)\times SU(3))/Z_3$ down to $(SU(3)\times SU(2)\times U(1))/ Z_6$, the gauge group of the Standard Model. We tentatively suggest a mechanism to stabilize the internal metric after that symmetry breaking and discuss a subsequent electroweak symmetry breaking at a different mass scale.Comment: 99 pages, 4 figure

Spatial Practices in Digital Work: Calling for a Spatial Turn in Information Systems Research

The growing use of digital media in the workplace is shifting work to digital platforms, this study explores the role of the physical office space in modern organisations where digital work is the norm. We capture the way in which digital media modulates the production of space by tracing the physical and digital interactions of a software development team in a global IT company. Taking a performative and ontogenetic view of space we conceptualise two types of spatial practices that form distinct modulations and assemblages of features of the physical and digital environment. The first spatial practice modulates space to support recurrent work activities, while the second spatial practice modulates space to support ephemeral and focused work activities. This study contributes to the IS literature with a conceptual basis to study the interconnected nature of physical space in digital work in modern workplace settings. It calls for greater attention to space as a performative and constitutive element of digital work in information systems research

Eco(il)logical Knowledge: on Different Ways of Relating with the Known

In this article, I narrate an ethnographic storyline that involves forest inhabitants, local politicians, development professionals, and scientific researchers in both representational and nonrepresentational worlds of knowing. I discuss how and why, in Angola, making forest knowledge through relations of distance to the forests is crucial for attaining institutional legitimacy over the forests. This way of acquiring authority and influence is championed by a broad epistemological tendency to address only the absent, which is then made present by accredited representers. Yet this technique disempowers local forest dwellers in their everyday territories and disallows the capacity that the ecological knowns have to reveal themselves. Knowing Angolan forests through absence and distance is not just a potent contemporary form of knowledge that qualifies as a way of ruling the forests, but is also integral to widespread (neo)colonial processes of distinction and separation: the knower and the known, the representer and the represented, the “cosmopolitan intellectual” and the “rustic bestial” Other. Finally, I discuss different forms of ecological knowledge in light of ethical stances toward knowing, relationality, and, ultimately, being.info:eu-repo/semantics/publishedVersio

Conceptualizing the Role of IS Security Compliance in Projects of Digital Transformation: Tensions and Shifts Between Prevention and Response Modes

Research shows that information systems security operates between two main distinct functioning modes, either prevention before a security incident occurs, or response which follows from an incident, usually external to the organisation. In this paper, we argue that this shift between prevention and response modes also happens due to inherent internal tensions created between pressures for digital transformation and the established forces for security compliance. We show how a digital transformation project introduced a security incident and challenged the IS security compliance function, reflecting the two different approaches to IS security in organizations. We conduct a participatory observation study of the implementation of Robotic Process Automation (RPA) in a financial services organization. We examine the shift from prevention to response in this project and identify generative drivers of digital transformation, and drivers of IS security compliance. Our analysis leads to the development of a process model that explains how organizations move from prevention to response when faced with tensions between IS security compliance and digital transformation

Exploring Co-presence Enabled Collaboration in Social Computing Inspired Enterprise Systems

This research describes the findings from an interpretive case study that explores the interplay between social computing (SC) and enterprise systems (ES). A fundamental shift is evident in how organisations become more effective through the adoption of SC capabilities. As process centric ES continues to pose challenges, an SC inspired, people-centric ES has become a medium for efficient interaction and collaboration across the divisions of an organisation. In this organisational reality, we explore the role of virtual co-presence of users on collaboration in ES. Our findings indicate that virtual co-presence enabled interactions, when focused and sustained over time, could facilitate collaboration for sharing of knowledge. An understanding of how users interact in mediated encounters contributes to our knowledge of how focused interactions may enable collaborations in ES. By drawing on the findings, the research seeks to outline some implications for the practice of a collaborative ES for the contemporary organisations

Acção humanitária: notas teôricas a relato de uma experiência pessoal

Nota Historica Permitam-me começar por proceder a uma breve introdução à história da acção humanitária e da sua evolução ao longo dos tempos, acção esta fundada em raízes judaico-cristãs. Trata-se de uma forma de intervenção que deriva de uma noção de caridade claramente paternalista, e se radica na Alta Idade Média, altura em que se começaram a formar os primeiros esboços do humanitarismo. É nesta altura que surgem os primeiros sinais de uma certa prática da medicina epidemiológica, que vei..

Toda a vastidão da terra

Historia de ficción en idioma original

Imputaçao de custos indirectos a projectos financiados de investigaçao. Estudo de caso na universidade do Minho

A prestaçâo de um serviço social com a utilizaçâo de recursos de urna forma eficaz e eficiente é o objectivo principal dos organismos públicos sem fins lucrativos. No que se refere ao financiamento de projectos de investigaçâo, normalmente as entidades financiadoras permitem que custos indirectos ou de estrutura sejam elegíveis até urna determinada percentagem do valor total aprovado ou elegível (designado por Overhead). Contudo esse valor, cuja gama de variaçâo se situa entre os 5% (Programa Alfa) e os 15/20% (IV Framework Programme, Socrates e Tempus) deve, regra gérai, ser justificado. Verifica-se assim a necessidade, por parte da Instituiçâo, de definir um modelo para o cálculo da repartiçâo de custos indirectos elegíveis (taxa de overhead), que permita justificar os valores inscritos nesta rubrica e, adicionalmente, permita inferir se a Instituiçâo se encontra a co-financiar os custos adicionáis originados por cada um dos projectos. Esta comunicaçâo é um resumo do Estudo elaborado entre Julho e Dezembro de 1998 e encontra-se dividida em duas partes. Na primeira parte é caracterizada a estrutura orgánica da Universidade do Minho e o seu actual tratamento contabilístico da informaçâo. Na segunda parte sao analisadas as respostas a inquéritos conduzidos e discutidos os respectivos resultados, terminando corn a apresentaçâo e justificaçâo da taxa de overhead que a Universidade do Minho deve aplicar nos projectos financiados de investigaçâo.The main objective of non profit public organisations is the provision of a social service with an efficient and effective resource use. In what concerns to the financing of research projects, financial entities usually allow indirect or strucutre costs to be elegible up to a certain percentage of the total approved or elegible project cost (designated Overhead). However this amount, whose range of variation stands between 5% (Alfa Programme) and 15/20% (IV Framework Programme) must, in general, be justified. Therefore, the Institution requires the definition of a suitable model to estimate the partition of elegible indirect costs (overhead tax), allowing the justification of the amounts requested in this item, and, additionally, allowing to infer if the Institution is financing additional costs brought about by any of the projects. This paper summarises a study carried out from July to December 1998 and is partitioned in two parts. The first one consists on the characterization of the organic structure of Universidade do Minho and its actual accounting information treatment system. In the second one, the answers to the conducted inquiries are analysed, its results discussed, ending with the suggestion and justification of the overhead tax that Universidade do Minho should adopt in research financed projects