Discrete and continuous symmetries in multi-Higgs-doublet models

We consider the Higgs sector of multi-Higgs-doublet models in the presence of simple symmetries relating the various fields. We construct basis invariant observables which may in principle be used to detect these symmetries for any number of doublets. A categorization of the symmetries into classes is required, which we perform in detail for the case of two and three Higgs doublets.Comment: 13 pages, RevTex, references adde

Preventing Atomicity Violations with Contracts

Software developers are expected to protect concurrent accesses to shared regions of memory with some mutual exclusion primitive that ensures atomicity properties to a sequence of program statements. This approach prevents data races but may fail to provide all necessary correctness properties.The composition of correlated atomic operations without further synchronization may cause atomicity violations. Atomic violations may be avoided by grouping the correlated atomic regions in a single larger atomic scope. Concurrent programs are particularly prone to atomicity violations when they use services provided by third party packages or modules, since the programmer may fail to identify which services are correlated. In this paper we propose to use contracts for concurrency, where the developer of a module writes a set of contract terms that specify which methods are correlated and must be executed in the same atomic scope. These contracts are then used to verify the correctness of the main program with respect to the usage of the module(s). If a contract is well defined and complete, and the main program respects it, then the program is safe from atomicity violations with respect to that module. We also propose a static analysis based methodology to verify contracts for concurrency that we applied to some real-world software packages. The bug we found in Tomcat 6.0 was immediately acknowledged and corrected by its development team

Basis invariant conditions for supersymmetry in the two-Higgs-doublet model

The minimal supersymmetric standard model involves a rather restrictive Higgs potential with two Higgs fields. Recently, the full set of classes of symmetries allowed in the most general two Higgs doublet model was identified; these classes do not include the supersymmetric limit as a particular class. Thus, a physically meaningful definition of the supersymmetric limit must involve the interaction of the Higgs sector with other sectors of the theory. Here we show how one can construct basis invariant probes of supersymmetry involving both the Higgs sector and the gaugino-higgsino Higgs interactions.Comment: RevTex, 11 pages, v2-small section adde

Articulation between information systems and quality management systems: literature review

Technological advancement has influenced all aspects of daily life. Since the adoption of Information Technology (IT) / Information Systems (IS), that represents the key issue for the success of most organizations, management of the quality of its products, services and business processes with established quality certification under ISO 9000, also represents a critical aspect in organizations. Organizations are forced to use advanced technologies and become more efficient in internal organization in order to be more competitive and closer to their customers and partners. In the face of increasingly demanding markets, interventions for organizational improvement through the adoption of quality management are becoming very common. The organizations are concerned with the development and implementation of information systems tailored to their specific needs, rather than buying in the market software applications. By the other hand, organizations acquire software certificates on the market to meet some specific requirements of the Quality Management Systems (QMS), such as auditing and document management. Synergies between the IS and QMS according to ISO 9001 standard, allows the association between these two systems, so that the IS can support and influence the processes related to the QMS, not only limited to the collection and documentation management. The joint development of these systems allows organizations to use only a methodology and a team intervention. The potential benefits of active participation of the organizational processes associated with the IS / QMS raises the need to develop a method that articulate/integrate interventions for improvement motivated by IT / IS with the improvement interventions motivated by the QMS.Fundação para a Ciência e a Tecnologia (FCT

Universities’ Entrepreneurship Education and Regional Development: a Stakeholders’ Approach

It is assumed that entrepreneurship education encourage the growth of new businesses, exploiting the entrepreneurial spirit within higher education sector. Additionally, entrepreneurship higher education is supposed to play a relevant role in the development of enterprising citizens and in the development regions through an ongoing process of knowledge creation and delivery. In this research we will explore what roles are attributed to entrepreneurship education in the literature with regard to regional development as well as the influence and relationship of the main intervening stakeholders. The aim is to present a conceptual model which integrate the contributions of both strands of literature and, at the same time, highlight the interplay between the several stakeholders involved in HEI’s entrepreneurship education and regional development.Entrepreneurship education, university, regional development, stakeholders

Dilemas iniciais na investigação em TSI: design science e design research, uma clarificação de conceitos

A inter-disciplinariedade dos sistemas de informação, disciplina aplicada e actividade de design, e o estudo sob o prisma de diferentes paradigmas traduz-se numa diversidade dos problemas abordados. O seu contexto é amplo e inclui questões importantes para além da tecnologia, como a aplicação, uso, eficácia, eficiência e seus impactos organizacionais e sociais. Enquanto design science, o interesse da investigação está na contribuição para a melhoria dos processos da própria actividade de design. A relevância da investigação em design science está associada ao resultado obtido para a melhoria das condições de vida em contexto organizacional, inter-organizacional e na Sociedade. Na investigação cujos resultados são artefactos, a adopção do design research, enquanto processo de investigação, é crucial para garantir disciplina, rigor e transparência. Baseado numa revisão de literatura, este artigo clarifica os termos design science e design research. Esta é a principal motivação para a apresentação deste artigo, determinante para a fase de investigação em tecnologias e sistemas de informação em que se encontram os três projectos de investigação apresentados. Como resultado, são discutidos os três projectos face aos conceitos de design science e design research.Fundação para a Ciência e a Tecnologia (FCT

Observing the temperature of the Big Bang through large scale structure

It is widely accepted that the Universe underwent a period of thermal equilibrium at very early times. One expects a residue of this primordial state to be imprinted on the large scale structure of space time. In this paper we study the morphology of this thermal residue in a universe whose early dynamics is governed by a scalar field. We calculate the amplitude of fluctuations on large scales and compare it to the imprint of vacuum fluctuations. We then use the observed power spectrum of fluctuations on the cosmic microwave background to place a constraint on the temperature of the Universe before and during inflation. We also present an alternative scenario where the fluctuations are predominantly thermal and near scale-invariant

Superradiant axion clouds around asteroid-mass primordial black holes

We analyze the dynamics and observational signatures of axion clouds formed via the superradiant instability around primordial black holes, focusing on the mass range $10^{14}-10^{18}$ kg where the latter may account for all the dark matter. We take into account the leading effects of axion self-interactions, showing that, even though these limit the number of axions produced within each cloud, a large number of superradiant axions become free of the black hole's gravitational potential and accumulate in the intergalactic medium or even in the host galaxy, depending on their escape velocity. This means that primordial black hole dark matter may lead to a sizeable astrophysical population of non-relativistic axions, with masses ranging from 0.1 eV to 1 MeV, depending on the primordial black hole mass and spin. We then show that if such axions couple to photons their contribution to the galactic and extragalactic background flux, mainly in the X-ray and gamma-ray band of the spectrum, is already beyond current observational limits for a large range of parameters that are, therefore, excluded. We finish by showing the prospects of the Athena X-ray telescope to further probe this co-existence of primordial black holes and axions.Comment: 21 pages, 5 figure