Causal Fermion Systems: A Quantum Space-Time Emerging from an Action Principle

Causal fermion systems are introduced as a general mathematical framework for formulating relativistic quantum theory. By specializing, we recover earlier notions like fermion systems in discrete space-time, the fermionic projector and causal variational principles. We review how an effect of spontaneous structure formation gives rise to a topology and a causal structure in space-time. Moreover, we outline how to construct a spin connection and curvature, leading to a proposal for a "quantum geometry" in the Lorentzian setting. We review recent numerical and analytical results on the support of minimizers of causal variational principles which reveal a "quantization effect" resulting in a discreteness of space-time. A brief survey is given on the correspondence to quantum field theory and gauge theories.Comment: 23 pages, LaTeX, 2 figures, footnote added on page

Inspiring minds: How big questions can build students’ epistemic insight and improve attitudes towards STEM

This article examines the impact that an ‘epistemically insightful’ approach to informal science learning can have on students’ attitudes, aspirations and perceptions of STEM subjects. It uses interim findings from a research and outreach project, including sustained Saturday activity programmes for ages14–16 and residential summer schools for ages 15–19, designed to create confident scholars who can engage with difficult philosophical questions raised by current technological advances. The Inspiring Minds project at Canterbury Christ Church University, Kent, UK, delivers informal science learning in schools and informal settings based on an epistemic insight-led approach to STEM outreach and education

Teaching sustainability and stewardship workshop 1: Collaborative approach to developing engagement with science and religion: Exploring sustainability in an international learning community

Workshop 1 introduces a collaborative approach to developing engagement with science and religion, by exploring sustainability in an international learning community of teachers based in Pakistan and England. The aim of the session was to begin to explore sustainability through science and religious worldviews. Participants were invited to: 1. Explore the meaning of the term ‘sustainability’ 2. Consider the relationship between science and religion 3. Reflect on the nature and communication of knowledge 4. Explore the Learning Community Blackboar

Science, religion and sustainability in schools: outlining a teacher learning community approach.

Sustainability is a large and growing field in educational research. Existing research has explored conceptually how the science/religion dialogue might inform sustainability education. This has the potential to enrich sustainability education by acknowledging difference and better engaging students across different religions and worldviews. Fostering a multidisciplinary approach to sustainability education in schools can help create connections between science, RE, geography, economics, and history, as these all contribute to critical thinking and inform compassionate action that supports social justice. Epistemically insightful approaches to teaching and learning have the potential to support this vital dialogue and push back against compartmentalization. In this presentation, we will discuss preliminary work and findings for our pilot study with ECTs, funded by the International Network for Science and Belief in Society. Our project will assess the potential of a cross-national (England and Pakistan) teacher research community model for co-creating resources and approaches that address the above issues of the conflict model, compartmentalization and lack of understanding/confidence in the delivery of sustainability education across different curriculum subjects

Supercritical multicomponent solvent coal extraction

The yield of organic extract from the supercritical extraction of coal with larger diameter organic solvents such as toluene is increased by use of a minor amount of from 0.1 to 10% by weight of a second solvent such as methanol having a molecular diameter significantly smaller than the average pore diameter of the coal

Information system support in construction industry with semantic web technologies and/or autonomous reasoning agents

Information technology support is hard to find for the early design phases of the architectural design process. Many of the existing issues in such design decision support tools appear to be caused by a mismatch between the ways in which designers think and the ways in which information systems aim to give support. We therefore started an investigation of existing theories of design thinking, compared to the way in which design decision support systems provide information to the designer. We identify two main strategies towards information system support in the early design phase: (1) applications for making design try-outs, and (2) applications as autonomous reasoning agents. We outline preview implementations for both approaches and indicate to what extent these strategies can be used to improve information system support for the architectural designer

Human centred design and evaluation of cabin interiors for business jet aircraft in virtual reality

In the recent past a growing attention to the passenger is emerging overall in the transport domain. Hence, maximising the quality of travelling from the human\u2019s point of view is a new challenge especially in those fields, such as aeronautics, in which technical efficiency, capacity and sustainability have traditionally driven the design process of systems and subsystems. In this context it is crucial to implement an efficient human centred design process in order to foresee the capability of a specific cabin interiors design of meeting the user\u2019s expectations, including the needs related to comfort and well being. By using virtual reality technologies as a vehicle/platform, it allows the users/passengers to experience the interior environment of the cabin long before the actual development and manufacturing of the full size demonstrator. Due to the complex nature of aerospace programmes, typically taking \u2018many\u2019 years to develop and productionise, technologies which help reduce programme risk and potential delays are hugely beneficial to all partners involved. In this paper we present the results of a virtual reality based evaluation campaign specifically conceived for the collection of potential users\u2019 feedback in the design of innovative and breakthrough solutions for the business jet industry. The main issues have regarded the identification of the expectation for such an elitist population and the creation of a Virtual Environment to explore the entire cabin as a holistic approach and innovative passenger experience. The work has been performed in the framework the Horizon 2020 project CASTLE (Cabin Systems Design Toward Passenger Well-being)

Quantum Oscillations in Cux_xBi2_2Se3_3 in High Magnetic Fields

Cu$_x$Bi$_2$Se$_3$ has drawn much attention as the leading candidate to be the first topological superconductor and the realization of coveted Majorana particles in a condensed matter system. However, there has been increasing controversy about the nature of its superconducting phase. This study sheds light on present ambiguity in the normal state electronic state, by providing a complete look at the quantum oscillations in magnetization in Cu$_x$Bi$_2$Se$_3$ at intense high fields up to 31T. Our study focuses on the angular dependence of the quantum oscillation pattern in a low carrier concentration. As magnetic field tilts from along the crystalline c-axis to ab-plane, the change of the oscillation period follows the prediction of the ellipsoidal Fermi surface. As the doping level changes, the 3D Fermi surface is found to transform into quasi-cylindrical at high carrier density. Such a transition is potentially a Lifshitz transition of the electronic state in Cu$_x$Bi$_2$Se$_3$.Comment: 6 pages, 6 figures, submitted to Phys. Rev.

Flip Distance Between Triangulations of a Simple Polygon is NP-Complete

Let T be a triangulation of a simple polygon. A flip in T is the operation of removing one diagonal of T and adding a different one such that the resulting graph is again a triangulation. The flip distance between two triangulations is the smallest number of flips required to transform one triangulation into the other. For the special case of convex polygons, the problem of determining the shortest flip distance between two triangulations is equivalent to determining the rotation distance between two binary trees, a central problem which is still open after over 25 years of intensive study. We show that computing the flip distance between two triangulations of a simple polygon is NP-complete. This complements a recent result that shows APX-hardness of determining the flip distance between two triangulations of a planar point set.Comment: Accepted versio

Combining polynomial chaos expansions and genetic algorithm for the coupling of electrophysiological models

The number of computational models in cardiac research has grown over the last decades. Every year new models with di erent assumptions appear in the literature dealing with di erences in interspecies cardiac properties. Generally, these new models update the physiological knowledge using new equations which reect better the molecular basis of process. New equations require the fi tting of parameters to previously known experimental data or even, in some cases, simulated data. This work studies and proposes a new method of parameter adjustment based on Polynomial Chaos and Genetic Algorithm to nd the best values for the parameters upon changes in the formulation of ionic channels. It minimizes the search space and the computational cost combining it with a Sensitivity Analysis. We use the analysis of di ferent models of L-type calcium channels to see that by reducing the number of parameters, the quality of the Genetic Algorithm dramatically improves. In addition, we test whether the use of the Polynomial Chaos Expansions improves the process of the Genetic Algorithm search. We conclude that it reduces the Genetic Algorithm execution in an order of 103 times in the case studied here, maintaining the quality of the results. We conclude that polynomial chaos expansions can improve and reduce the cost of parameter adjustment in the development of new models.Peer ReviewedPostprint (author's final draft