Hearing Emergence: Towards Sound-Based Self-Organisation

A fascination for models derived from natural organisation of organisms has a long history of influence in the arts. This paper discusses emergence as a complex behaviour and its manifestations in the sonic domain. We address issues inherent in the use of visual/spatial metaphors for sonic representation and propose an approach based on sound interaction within biological complex systems

Natural Selection: A Stethoscopic Amphibious Installation.

This paper discusses emergence as a complex behaviour in the sound domain and presents a design strategy that was used in the creation of the sound installation Natural Selection to encourage the perception of sonic emergence. The interactions in Natural Selection are based on an algorithm derived from an innately sonic emergent ecological system found in nature, that of mating choices by female frogs within a calling male frog chorus. This paper outlines the design and implementation of the installation and describes the research behind its design, most notably the notion of embodiment within a sonic environment and its importance to the perception of sonic emergence

Avenues for private climate change litigation: the advancement of a South African constitutional rights approach

A second wave of climate litigation targeting private defendants has gained momentum due to advances in attribution science and the legal discourse surrounding the responsibility of ‘carbon majors’ who knowingly pollute. At the same time, rights-based arguments are seeing increasing success in public litigation targeting governments who fail to take appropriate action to prevent climate change. This Paper explores the potential for rights-based arguments in the private context, specifically on the African continent. It argues that the horizontal application of an environmental right, both directly and indirectly, enjoys firm judicial recognition in certain African jurisdictions. As a result, Africa is ripe for substantive engagement with environmental rights and their application to private entities despite having few cases of climate litigation. More narrowly, this Paper investigates the constitutional milieu of the South African right to a healthy environment and argues for a substantive engagement with the transformative nature of such a right as opposed to relying solely on procedural approaches to obtaining environmental justice

A Simple Method to detect spontaneous CP Violation in multi-Higgs models

For models with several Higgs doublets we present an alternative method to the one proposed by Branco, Gerard and Grimus, in 1984, to check whether or not CP is spontaneously violated in the Higgs potential. The previous method is powerful and rigorous. It requires the identification of a matrix $U$ corresponding to a symmetry of the Lagrangian and verifying a simple relation involving the vacuum expectation values. The nonexistence of such a matrix signals spontaneous CP violation. However, as the number of Higgs doublets increases, finding such a matrix $U$ may not be straightforward and it may turn out to be easier to analyse the potential by going to the so-called Higgs basis. The transformation to the Higgs basis is straightforward once the vacuum expectation values are known. The method proposed in this work is also powerful and rigorous and can be particularly useful to analyse models with more than two Higgs doublets and with continuous symmetries.Comment: 9 pages, no figures. v2: minor changes, matching JHEP versio

Poseidon Principles: Legal Directions for Implementation & Enforcement

A group of global banks led by Citi, Société Générale and Danske Bank have collaborated to formulate a framework known as the Poseidon Principles, which will limit lending to shipping companies that fail to uphold increasing environmental standards. Signatories to the green deal will integrate climate considerations into lending decisions with the objective of achieving decarbonisation in the industry. This raises a number of questions pertaining to the contractual obligations that Signatories will impose on Borrowers in their financing agreements. This Paper specifically addresses the question of enforceability and the legal consequence of the Poseidon Principles Standard Covenant Clause (SCC), its available remedy, and the incorporation of environmental obligations into financing agreements. This Paper calls for a gradual implementation of stricter enforcement mechanisms as a set of green norms become increasingly pervasive throughout the shipping sector. The Poseidon Principles framework can become a powerful private governance tool in achieving international climate change goals through providing both directional industry guidance and legal avenues for accountability

Implications of symmetries in the scalar sector

Symmetries play a very important r\^ole in Particle Physics. In extended scalar sectors, the existence of symmetries may permit the models to comply with the experimental constraints in a natural way, and at the same time reduce the number of free parameters. There is a strong interplay among internal symmetries of the scalar potential, its CP properties and mass degeneracies of the physical scalars. Some of these aspects were discussed in this talk.Comment: 8 pages, to be published in the Proceedings of DISCRETE2018: 6th Symposium on Prospects in the Physics of Discrete Symmetries, 26-30 Nov 2018. Vienna, Austri

Spontaneous symmetry breaking in the S3S_3-symmetric scalar sector

We present a detailed study of the vacua of the $S_3$-symmetric three-Higgs-doublet potential, specifying the region of parameters where these minimisation solutions occur. We work with a CP conserving scalar potential and analyse the possible real and complex vacua with emphasis on the cases in which the CP symmetry can be spontaneously broken. Results are presented both in the reducible-representation framework of Derman, and in the irreducible-representation framework. Mappings between these are given. Some of these implementations can in principle accommodate dark matter and for that purpose it is important to identify the residual symmetries of the potential after spontaneous symmetry breakdown. We are also concerned with constraints from vacuum stability.Comment: 37 pages. v2: Minor changes in the references, matches published version. v3: Table 6 corrected: two additional cases conserve CP. Related discussion adapted. Version consistent with JHEP Erratu

Symmetries and Mass Degeneracies in the Scalar Sector

We explore some aspects of models with two and three SU(2) scalar doublets that lead to mass degeneracies among some of the physical scalars. In Higgs sectors with two scalar doublets, the exact degeneracy of scalar masses, without an artificial fine-tuning of the scalar potential parameters, is possible only in the case of the inert doublet model (IDM), where the scalar potential respects a global U(1) symmetry that is not broken by the vacuum. In the case of three doublets, we introduce and analyze the replicated inert doublet model, which possesses two inert doublets of scalars. We then generalize this model to obtain a scalar potential, first proposed by Ivanov and Silva, with a CP4 symmetry that guarantees the existence of pairwise degenerate scalar states among two pairs of neutral scalars and two pairs of charged scalars. Here, CP4 is a generalized CP symmetry with the property that $({\rm CP}4)^n$ is the identity operator only for integer $n$ values that are multiples of 4. The form of the CP4-symmetric scalar potential is simplest when expressed in the Higgs basis, where the neutral scalar field vacuum expectation value resides entirely in one of the scalar doublet fields. The symmetries of the model permit a term in the scalar potential with a complex coefficient that cannot be removed by any redefinition of the scalar fields within the class of Higgs bases (in which case, we say that no real Higgs basis exists). A striking feature of the CP4-symmetric model is that it preserves CP even in the absence of a real Higgs basis, as illustrated by the cancellation of the contributions to the CP violating form factors of the effective ZZZ and ZWW vertices.Comment: 52 pages, 2 figures, second revised version with new material, as published by JHE