Teaching TEI: The Need for TEI by Example

The Text Encoding Initiative (TEI)1 has provided a complex and comprehensive system of provisions for scholarly text encoding. Although a major focus of the ‘digital humanities’ domain, and despite much teaching effort by the TEI community, there is a lack of teaching materials available, which would encourage the adoption of the TEI's recommendations and the widespread use of its text encoding guidelines in the wider academic community. This article describes the background, plans, and aims of the TEI by Example project, and why we believe it is a necessary addition to the materials currently provided by the TEI itself. The teaching materials currently available are not suited to the needs of self directed learners, and the development of stand alone, online tutorials in the TEI are an essential addition to the extant resources, in order to encourage and facilitate the uptake of TEI by both individuals and institutions

Domain wall partition functions and KP

We observe that the partition function of the six vertex model on a finite square lattice with domain wall boundary conditions is (a restriction of) a KP tau function and express it as an expectation value of charged free fermions (up to an overall normalization).Comment: 16 pages, LaTeX2

Dynamics of a quasi-quadratic map

We consider the map \cchi:\Q\to\Q given by \cchi(x)= x\ceil{x}, where \ceil{x} denotes the smallest integer greater than or equal to $x$, and study the problem of finding, for each rational, the smallest number of iterations by \cchi that sends it into an integer. Given two natural numbers $M$ and $n$, we prove that the set of numerators of the irreducible fractions that have denominator$M$ and whose orbits by \cchi reach an integer in exactly $n$ iterations is a disjoint union of congruence classes modulo $M^{n+1}$. Moreover, we establish a finite procedure to determine them. We also describe an efficient algorithm to decide if an orbit of a rational number bigger than one fails to hit an integer until a prescribed number of iterations have elapsed, and deduce that the probability that such an orbit enters $\Z$ is equal to one.Fundação para a Ciência e a Tecnologia (FCT

Classicality in discrete Wigner functions

Gibbons et al. [Phys. Rev. A 70, 062101(2004)] have recently defined a class of discrete Wigner functions W to represent quantum states in a Hilbert space with finite dimension. We show that the only pure states having non-negative W for all such functions are stabilizer states, as conjectured by one of us [Phys. Rev. A 71, 042302 (2005)]. We also show that the unitaries preserving non-negativity of W for all definitions of W form a subgroup of the Clifford group. This means pure states with non-negative W and their associated unitary dynamics are classical in the sense of admitting an efficient classical simulation scheme using the stabilizer formalism.Comment: 10 pages, 1 figur

On the thermodynamic limit of form factors in the massless XXZ Heisenberg chain

We consider the problem of computing form factors of the massless XXZ Heisenberg spin-1/2 chain in a magnetic field in the (thermodynamic) limit where the size M of the chain becomes large. For that purpose, we take the particular example of the matrix element of the third component of spin between the ground state and an excited state with one particle and one hole located at the opposite ends of the Fermi interval (umklapp-type term). We exhibit its power-law decrease in terms of the size of the chain M, and compute the corresponding exponent and amplitude. As a consequence, we show that this form factor is directly related to the amplitude of the leading oscillating term in the long-distance asymptotic expansion of the two-point correlation function of the third component of spin.Comment: 28 page

Some families of density matrices for which separability is easily tested

We reconsider density matrices of graphs as defined in [quant-ph/0406165]. The density matrix of a graph is the combinatorial laplacian of the graph normalized to have unit trace. We describe a simple combinatorial condition (the "degree condition") to test separability of density matrices of graphs. The condition is directly related to the PPT-criterion. We prove that the degree condition is necessary for separability and we conjecture that it is also sufficient. We prove special cases of the conjecture involving nearest point graphs and perfect matchings. We observe that the degree condition appears to have value beyond density matrices of graphs. In fact, we point out that circulant density matrices and other matrices constructed from groups always satisfy the condition and indeed are separable with respect to any split. The paper isolates a number of problems and delineates further generalizations.Comment: 14 pages, 4 figure

Evaluating events data for cultural analytics : a case study on the economic and social effects of Covid-19 on the Edinburgh Festivals

Funding: This work was supported by the Arts and Humanities Research Council under Grant AH/W007533/1.The effects of the Covid-19 pandemic on the Creative and Cultural Industries can be difficult to quantify. Metadata about events (theatre productions, music and comedy gigs, sporting fixtures, days out, and more) are an untapped resource for cultural analytics that can be used as a proxy metric for financial and social impact. This article uses a sample of large-scale cultural events data from UK industry providers Data Thistle to ask: how can events data at scale be used to quantify the financial and social effects of the Covid-19 pandemic on the cultural events sector in a particular region? We analysed the changes in event provision in Edinburgh in August 2018, 2019, 2020 and 2021, revealing an estimated 97.3% fall in ticketing revenue between 2019 and 2020. Additionally, the effects that pandemic restrictions had on different categories of event reveal a disparity in how different audience sectors were affected, with ‘Visual Art’ and ‘Days Out’ showing most resilience and ‘Theatre’, ‘Comedy’ and ‘LGBT’ events being most reduced. Our findings indicate that events data are a rich but heterogenous source of information regarding the cultural and creative economy, which is not yet routinely used by researchers.Peer reviewe

Cultural analytics in the UK:Events data potential for the creative and cultural industries

This article investigates the potential for novel research utilising data generated by the Creative and Cultural Industries (CCI) in the UK, focussing on the long tail of metadata associated with the UK’s rich cultural events landscape. We conducted semi-structured interviews with 29 researchers and related domain experts to ascertain: (1) How cultural data is valued by academic, social and industry research in the UK and how this relates to how culture is valued; (2) How large-scale cultural events data fits into the existing landscape of cultural data; (3) How UK research can make better use of cultural events data (skills and infrastructure); (4) The benefits and pitfalls of an evidence-based approach to cultural policy; and (5) The repercussions of the Covid-19 pandemic on how data-led work is positioned within the CCI. We advocate for the potential value of cultural events data to academic research, policy and industry, and also for a humanities-led approach to counter the trends towards data-driven understandings of and appraisal of culture. We suggest that a centralised cultural events data service for use in research, industry and policy is one way of supporting this

Wigner distributions for non Abelian finite groups of odd order

Wigner distributions for quantum mechanical systems whose configuration space is a finite group of odd order are defined so that they correctly reproduce the marginals and have desirable transformation properties under left and right translations. While for the Abelian case we recover known results, though from a different perspective, for the non Abelian case, our results appear to be new.Comment: Latex, 9 pages, text restructured and some new material adde