Full counting statistics for interacting trapped fermions

We study NN spinless fermions in their ground state confined by an external potential in one dimension with long range interactions of the general Calogero-Sutherland type. For some choices of the potential this system maps to standard random matrix ensembles for general values of the Dyson index \betaβ. In the fermion model \betaβ controls the strength of the interaction, \beta=2β=2 corresponding to the noninteracting case. We study the quantum fluctuations of the number of fermions N_DND in a domain DD of macroscopic size in the bulk of the Fermi gas. We predict that for general \betaβ the variance of N_DND grows as A_{\beta} \log N + B_{\beta}AβlogN+Bβ for N \gg 1N≫1 and we obtain a formula for A_\betaAβ and B_\betaBβ. This is based on an explicit calculation for \beta\in\left\{ 1,2,4\right\}β∈{1,2,4} and on a conjecture that we formulate for general \betaβ. This conjecture further allows us to obtain a universal formula for the higher cumulants of N_DND. Our results for the variance in the microscopic regime are found to be consistent with the predictions of the Luttinger liquid theory with parameter K = 2/\betaK=2/β, and allow to go beyond. In addition we present families of interacting fermion models in one dimension which, in their ground states, can be mapped onto random matrix models. We obtain the mean fermion density for these models for general interaction parameter \betaβ. In some cases the fermion density exhibits interesting transitions, for example we obtain a noninteracting fermion formulation of the Gross-Witten-Wadia model.

Emergent Interfaces: Vague, Complex, Bespoke and Embodied Interaction between Humans and Computers

Most Human–Computer Interfaces are built on the paradigm of manipulating abstract representations. This can be limiting when computers are used in artistic performance or as mediators of social connection, where we rely on qualities of embodied thinking: intuition, context, resonance, ambiguity and fluidity. We explore an alternative approach to designing interaction that we call the emergent interface: interaction leveraging unsupervised machine learning to replace designed abstractions with contextually derived emergent representations. The approach offers opportunities to create interfaces bespoke to a single individual, to continually evolve and adapt the interface in line with that individual’s needs and affordances, and to bridge more deeply with the complex and imprecise interaction that defines much of our non-digital communication. We explore this approach through artistic research rooted in music, dance and AI with the partially emergent system Sonified Body. The system maps the moving body into sound using an emergent representation of the body derived from a corpus of improvised movement from the first author. We explore this system in a residency with three dancers. We reflect on the broader implications and challenges of this alternative way of thinking about interaction, and how far it may help users avoid being limited by the assumptions of a system’s designer.

Improved Face Recognition With Fractal-Based Texture Analysis

Fractals are useful to uniquely represent texture in the human face, which serves as an equivalent of human vision. FaceNet, calculating face descriptors of a person, has been observed to perform with setbacks when several factors of occlusion are present. This paper proposes a new methodology that exploits the self-similar patterns in a person's face to highlight and enhance regions of high texture in a facial image. The system maps the original image into a representation in the pre-processing stage of computer vision. This representation when fed as an input to the FaceNet CNN optimizes the face embedding generated. An SVM classifier separates the hard positive examples from the hard negative examples during classification. The model is trained using YouTube Faces DB as primary dataset and for validation; a custom dataset is designed to verify a person's identity despite the presence of secondary factors such as expressions and forgery. The proposed model attained an overall accuracy of 96.73% with the YouTube Faces DB, and a notable reduction in the false positive rates is observed.

Coherently amplifying photon production from vacuum with a dense cloud of accelerating photodetectors

An accelerating photodetector is predicted to see photons in the electromagnetic vacuum. However, the extreme accelerations required have prevented the direct experimental verification of this quantum vacuum effect. In this work, we consider many accelerating photodetectors that are contained within an electromagnetic cavity. We show that the resulting photon production from the cavity vacuum can be collectively enhanced such as to be measurable. The combined cavity-photodetectors system maps onto a parametrically driven Dicke-type model; when the detector number exceeds a certain critical value, the vacuum photon production undergoes a phase transition from a normal phase to an enhanced superradiant-like, inverted lasing phase. Such a model may be realized as a mechanical membrane with a dense concentration of optically active defects undergoing gigahertz flexural motion within a superconducting microwave cavity. We provide estimates suggesting that recent related experimental devices are close to demonstrating this inverted, vacuum photon lasing phase.

Research and Assessment of Biogas Composition at the TKO Running and Recommendations for Its Use

The article deals with the main problems, namely the emission of biogas into the atmospheric air, during operation and after the closure of MSW landfills. Biogas, which contains methane, is considered not only as a strong greenhouse gas, but also as a valuable fuel that can be used as an energy resource. To assess the biogas potential at the operating landfill, field studies were carried out, which made it possible to determine the intensity and composition of gas emissions. The main points of landfill gas sampling at the landfill have been selected. Methods have been worked out and the equipment necessary for environmental monitoring at a real operating landfill has been selected. Using gas-geochemical surveys, environmental monitoring of biogas emissions from the MSW landfill was carried out at 49 sampling points. Coordinates in the WGS84 coordinate system, maps of the concentration distribution of the main components of biogas (methane, hydrogen sulfide, carbon dioxide, oxygen) were obtained at a depth of 50 cm from the surface of the landfill body. A zone recommended for drilling biogas wells was selected and recommendations were developed for installing a degassing station and using biogas as a source of electricity

Coherently amplifying photon production from vacuum with a dense cloud of accelerating photodetectors

We consider N>>1 accelerating (i.e., oscillating) photodetectors modeled as two level systems (TLSs) that are contained within a microwave cavity and show that the resulting photon production from vacuum can be collectively enhanced such as to be measurable. The cavity-accelerating TLSs system maps onto a parametrically driven Dicke-type model and when the detector number N exceeds a certain critical value, the vacuum photon production undergoes a phase transition from a normal phase to an enhanced superradiant-like, inverted lasing phase. Such a model may be realized as a mechanical membrane with a dense concentration of optically active defects undergoing GHz flexural motion and contained within a 3D, superconducting microwave cavity. We show that recent related experimental devices are close to demonstrating this inverted, vacuum photon lasing phase.

Building a system-based Theory of Change using Participatory Systems Mapping

Theory of Change diagrams are commonly used within evaluation. Due to their popularity and flexibility, Theories of Change can vary greatly, from the nuanced and nested, through to simplified and linear. We present a methodology for building genuinely holistic, complexity-appropriate, system-based Theory of Change diagrams, using Participatory Systems Mapping as a starting point. Participatory System Maps provide a general-purpose resource that can be used in many ways; however, knowing how to turn their complex view of a system into something actionable for evaluation purposes is difficult. The methodology outlined in this article gives this starting point and plots a path through from systems mapping to a Theory of Change evaluators can use. It allows evaluators to develop practical Theories of Change that take into account feedbacks, wider context and potential negative or unexpected outcomes. We use the example of the energy trilemma map presented elsewhere in this special issue to demonstrate.

Applying a Systemic Approach to Gender Transport Poverty

Transport poverty and the associated levels of deprivation experienced by women is a ‘wicked problem'. A systemic approach is needed to address entrenched societal and cultural norms that deprive women of equality and agency. The conceptual shift from ‘transport’ to ‘mobility’, emphasising access to life opportunities, provides an opportunity for more systems approaches to be tried. The ‘WEMOBILE project’ addressed gender transport poverty in Low-Middle-Income Countries using ethnographic and empathic design approaches to understand and re(present) the effects of gender transport poverty. This article focusses on insights provided by employing a systemic design to data gathered in Pakistan. In represent­ting data as system maps, gaps that hinder the effectiveness of existing solutions are emphasised as well as the usefulness of this approach in highlighting opportunities for policy and opera­tional changes. Keywords: Empathy, gender-sensitive transport, systems-thinking, Low-Middle-Income Countries, Pakistan.