All orders structure and efficient computation of linearly reducible elliptic Feynman integrals

We define linearly reducible elliptic Feynman integrals, and we show that they can be algorithmically solved up to arbitrary order of the dimensional regulator in terms of a 1-dimensional integral over a polylogarithmic integrand, which we call the inner polylogarithmic part (IPP). The solution is obtained by direct integration of the Feynman parametric representation. When the IPP depends on one elliptic curve (and no other algebraic functions), this class of Feynman integrals can be algorithmically solved in terms of elliptic multiple polylogarithms (eMPLs) by using integration by parts identities. We then elaborate on the differential equations method. Specifically, we show that the IPP can be mapped to a generalized integral topology satisfying a set of differential equations in $\epsilon$-form. In the examples we consider the canonical differential equations can be directly solved in terms of eMPLs up to arbitrary order of the dimensional regulator. The remaining 1-dimensional integral may be performed to express such integrals completely in terms of eMPLs. We apply these methods to solve two- and three-points integrals in terms of eMPLs. We analytically continue these integrals to the physical region by using their 1-dimensional integral representation.Comment: The differential equations method is applied to linearly reducible elliptic Feynman integrals, the solutions are in terms of elliptic polylogarithms, JHEP version, 50 page

The Zeldovich & Adhesion approximations, and applications to the local universe

The Zeldovich approximation (ZA) predicts the formation of a web of singularities. While these singularities may only exist in the most formal interpretation of the ZA, they provide a powerful tool for the analysis of initial conditions. We present a novel method to find the skeleton of the resulting cosmic web based on singularities in the primordial deformation tensor and its higher order derivatives. We show that the A_3-lines predict the formation of filaments in a two-dimensional model. We continue with applications of the adhesion model to visualise structures in the local (z < 0.03) universe.Comment: 9 pages, 8 figures, Proceedings of IAU Symposium 308 "The Zeldovich Universe: Genesis and Growth of the Cosmic Web", 23-28 June 2014, Tallinn, Estoni

Adoption of IS Development Methods Across Cultural Boundaries

In IS practice as well as in the literature, IS development methods are prominently espoused. IS development methods are used around the world and globalization of business stimulates their harmonization. To our knowledge, no empirical research has been reported regarding the effect of national cultures on the actual (non-)adoption of IS development methods, which is the focus of this research project. The study is based on Hofstedes well-known research (conducted within IBM), which has provided a conceptual foundation for cross-national research over the past two decades. Data encompassing approximately 40 countries were collected within one global consulting firm. The outcomes of this study are expected to have implications for how global organizations can introduce new development methods more effectively

In an Article Written by Henry Hidding Dated 12 March 1912 About the Ninth Street Church or the Pillar Church and Published in the Holland City News on the 14th of March

In an article written by Henry Hidding dated 12 March 1912 about the Ninth Street Church or the Pillar Church and published in the Holland City News on the 14th of March, the author related the meeting in the church during the Civil War in which Dr. Albertus C. Van Raalte participated in the recruitment of soldiers for Company 1 of the 25th Michigan Infantry. Van Raalte had opened the meeting which was lengthy and gave an address. Hidding had been at this lengthy meeting and related his memories of the event.https://digitalcommons.hope.edu/vrp_1910s/1002/thumbnail.jp

The Zeldovich approximation: key to understanding Cosmic Web complexity

We describe how the dynamics of cosmic structure formation defines the intricate geometric structure of the spine of the cosmic web. The Zeldovich approximation is used to model the backbone of the cosmic web in terms of its singularity structure. The description by Arnold et al. (1982) in terms of catastrophe theory forms the basis of our analysis. This two-dimensional analysis involves a profound assessment of the Lagrangian and Eulerian projections of the gravitationally evolving four-dimensional phase-space manifold. It involves the identification of the complete family of singularity classes, and the corresponding caustics that we see emerging as structure in Eulerian space evolves. In particular, as it is instrumental in outlining the spatial network of the cosmic web, we investigate the nature of spatial connections between these singularities. The major finding of our study is that all singularities are located on a set of lines in Lagrangian space. All dynamical processes related to the caustics are concentrated near these lines. We demonstrate and discuss extensively how all 2D singularities are to be found on these lines. When mapping this spatial pattern of lines to Eulerian space, we find a growing connectedness between initially disjoint lines, resulting in a percolating network. In other words, the lines form the blueprint for the global geometric evolution of the cosmic web.Comment: 37 pages, 21 figures, accepted for publication in MNRA

The Era of the Martyrs

In this book, Aaltje Hidding presents the first synthesis about how the Great Persecution (303–313 CE) was remembered in Late Antique Egypt. She unites research methods in memory studies with cognitive science and bases herself on archaeological, literary, papyrological and epigraphical sources in order to analyse how the Persecution was represented and remembered in three different cities along the Nile: Oxyrhynchus, Antinoopolis and Dendara

Caustic Skeleton & Cosmic Web

We present a general formalism for identifying the caustic structure of an evolving mass distribution in an arbitrary dimensional space. For the class of Hamiltonian fluids the identification corresponds to the classification of singularities in Lagrangian catastrophe theory. Based on this we develop a theoretical framework for the formation of the cosmic web, and specifically those aspects that characterize its unique nature: its complex topological connectivity and multiscale spinal structure of sheetlike membranes, elongated filaments and compact cluster nodes. The present work represents an extension of the work by Arnol'd et al., who classified the caustics for the 1- and 2-dimensional Zel'dovich approximation. His seminal work established the role of emerging singularities in the formation of nonlinear structures in the universe. At the transition from the linear to nonlinear structure evolution, the first complex features emerge at locations where different fluid elements cross to establish multistream regions. The classification and characterization of these mass element foldings can be encapsulated in caustic conditions on the eigenvalue and eigenvector fields of the deformation tensor field. We introduce an alternative and transparent proof for Lagrangian catastrophe theory, and derive the caustic conditions for general Lagrangian fluids, with arbitrary dynamics, including dissipative terms and vorticity. The new proof allows us to describe the full 3-dimensional complexity of the gravitationally evolving cosmic matter field. One of our key findings is the significance of the eigenvector field of the deformation field for outlining the spatial structure of the caustic skeleton. We consider the caustic conditions for the 3-dimensional Zel'dovich approximation, extending earlier work on those for 1- and 2-dimensional fluids towards the full spatial richness of the cosmic web

The Era of the Martyrs

In this book, Aaltje Hidding presents the first synthesis about how the Great Persecution (303–313 CE) was remembered in Late Antique Egypt. She unites research methods in memory studies with cognitive science and bases herself on archaeological, literary, papyrological and epigraphical sources in order to analyse how the Persecution was represented and remembered in three different cities along the Nile: Oxyrhynchus, Antinoopolis and Dendara