Single-Field Inflation and the Local Ansatz: Distinguishability and Consistency

The single-field consistency conditions and the local ansatz have played separate but important roles in characterizing the non-Gaussian signatures of single- and multifield inflation respectively. We explore the precise relationship between these two approaches and their predictions. We demonstrate that the predictions of the single-field consistency conditions can never be satisfied by a general local ansatz with deviations necessarily arising at order $(n_s-1)^2$. This implies that there is, in principle, a minimum difference between single- and (fully local) multifield inflation in observables sensitive to the squeezed limit such as scale-dependent halo bias. We also explore some potential observational implications of the consistency conditions and its relationship to the local ansatz. In particular, we propose a new scheme to test the consistency relations. In analogy with delensing of the cosmic microwave background, one can deproject the coupling of the long wavelength modes with the short wavelength modes and test for residual anomalous coupling.Comment: 17 page

Bosonization of World-Sheet Fermions in Minkowski Space-Time

We propose a way of bosonizing free world-sheet fermions for $4$-dimensional heterotic string theory formulated in Minkowski space-time. We discuss the differences as compared to the standard bosonization performed in Euclidean space-time.Comment: 1+9 pages, TeX macros include

Summability of Superstring Theory

Several arguments are given for the summability of the superstring perturbation series. Whereas the Schottky group coordinatization of moduli space may be used to provide refined estimates of large-order bosonic string amplitudes, the super-Schottky group variables define a measure for the supermoduli space integral which leads to upper bounds on superstring scattering amplitudes.Comment: 11 pages, TeX. A remark about C-cycles and dividing cycles and two references have been added to the pape

Exploring workplace innovation in diverse and low-skilled settings:Reflections on using Critical Utopian Action Research

What are the strengths and weaknesses of applying Action Research to Workplace Innovation in low-skilled sectors? This article reflects on an Action Research project conducted in April 2021 with participant employees from an ethnically diverse and purportedly “low-skilled” workforce of a German medium-sized company. Using the novel Nordic research method called Critical Utopian Action Research (CUAR), which emphasises utopianism, emancipation and democratic engagement (Egmose et al., 2020), the participant group was found to discuss perspectives and obstacles for workplace development. In the analysis and reflections, we present the methodological outcomes of the project and explore the nuances of implementing this specific method through the tensions between individual and group identity within “Workplace Innovation”. After a short theoretical review to contextualise Workplace Innovation within discussions of diverse and low-skilled workforces, the article offers detailed descriptions of the CUAR process undertaken. Following analysis of the difficulties encountered applying CUAR to Workplace Innovations in this context, the article concludes by addressing the importance of adapting the procedure and exercises of (Critical Utopian) Action Research to small-sized research projects. It further illustrates the method’s potential to promote a socially-driven and participatory approach to Workplace Innovation, whilst emphasising the need for more research projects in this area to be conducted for (and with) workforces considered both “low-skilled” and ethnically diverse

Is there scale-dependent bias in single-field inflation?

Scale-dependent halo bias due to local primordial non-Gaussianity provides a strong test of single-field inflation. While it is universally understood that single-field inflation predicts negligible scale-dependent bias compared to current observational uncertainties, there is still disagreement on the exact level of scale-dependent bias at a level that could strongly impact inferences made from future surveys. In this paper, we clarify this confusion and derive in various ways that there is exactly zero scale-dependent bias in single-field inflation. Much of the current confusion follows from the fact that single-field inflation does predict a mode coupling of matter perturbations at the level of f_(NL)^(local); ≈ −5/3, which naively would lead to scale-dependent bias. However, we show explicitly that this mode coupling cancels out when perturbations are evaluated at a fixed physical scale rather than fixed coordinate scale. Furthermore, we show how the absence of scale-dependent bias can be derived easily in any gauge. This result can then be incorporated into a complete description of the observed galaxy clustering, including the previously studied general relativistic terms, which are important at the same level as scale-dependent bias of order f_(NL)^(local) ~ 1. This description will allow us to draw unbiased conclusions about inflation from future galaxy clustering data

SymbioCity: reconceptualising the future of the shopping mall

Architecture, and the concept of produced space, cannot be divorced from the basic notion of society and, with this, social integration and social interaction. This thesis considers the massive potential, and missed opportunity, which the suburban shopping mall offers as a socio-economic community framework within the urban landscape. Malls have become principal sites of social communion while resisting adaptation to this new public agenda and have become disconnected from the city. Shopping has historically always been an open, public and social forum, forming an integrated part of society and the city. With the proliferation of the car and the consequent urban sprawl, however, retail has evolved into a typology that is an isolated and single-use phenomenon in the shape of the shopping mall. It is exclusive in its nature and context, and becomes a barrier to the notion of community, particularly in South Africa where this model seems to negate safety concerns but does not consider human dignity. The disconnection and lack of connectivity and access forces the architecture to become a themed space where branding is overriding and diversity is extremely limited. The public street has been privatised and becomes quasi-public; social interaction is forced to take place in a privately controlled pseudo-urban environment that turns its back on the city and the scale and texture of urbanity becomes eroded. Urban planning and current legislation permit these massive single-use forms to develop, allowing fragmented spatial and social proximities to occur without the benefit of the synergies of uses that take place as happens in naturally evolving cities. The introduction of a complimentary mix of uses will allow the mall to become a truly integrated and city-like resource. The current model is also unsustainable when viewed holistically in terms of the balanced triumvirate of economy, environment and equity, known as the ‘triple bottom line’. The mall creates a massive carbon footprint and, as part of the existing produced stock that functions well as a commercial model, needs to adapt to contemporary social and environmental needs, as well as those of the future. Opportunities for symbiotic relationships will be explored and will be introduced wherein there is a mutual and beneficial sharing of resources of both the mall and the city around it. The malls’ current form is one wherein resources are both heavily consumes and wasted. Symbiosis will form a vital and integral paradigm for looking at a mixeduse intervention where the retail, in the form of the mall, once again forms an integrated part of the city and feeds back into it. The mall will become a symbiotic typology, deriving from and linking into the urban fabric, becoming the street again, from where its roots are derived. This symbiotic paradigm will be further extended within all systems of the intervention and the mall will now become a generator of resources as apposed to its current form as a consumer of resources. Keywords: shopping, urbanity, typology, quasi-public, street, unsustainable, symbiosis QUESTION I will be dealing with the concept of the shopping mall and the inherent dichotomy of public and private space. With this, the social consequences of the suburban model as a private retail spatial phenomenon that appropriates part of the city to itself and the question of how we reconceptualise its future through symbiotic relationships in order that it relinquishes this space back to the city and the public