bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cities
Authors: Galès Patrick Le , Zagrodzki Mathieu 
Published: November 2023

Abstract
From the integrated medieval European cities surrounded by walls, to the colonial Boston or the rapidly growing Phoenix, Las Vegas, or South East London, the category ‘city’ comprises diﬀerent densities, borders, and dimensions; for instance: the material city of walls, squares, houses, roads, lights, utilities, buildings, waste, and physical infrastructure; the cultural city in terms of imagination, diﬀerence, representations, ideas, symbols, art, texts, senses, religion, and aesthetics; the politics and policies of the city in terms of domination, power, government, mobilization, welfare, and education; the social city of riots, ethnic, economic, or gender inequalities, everyday life and social movements; the economy of the city: division of labor, scale, production, consumption, trade Urban areas are robust beasts.
Strategies in problem solving
Authors: Tao Terence 
Published: November 2023

Abstract
Like and unlike the proverb above, the solution to a problem begins (and continues, and ends) with simple, logical steps. But as long as one steps in a firm, clear direction, with long strides and sharp vision, one would need far, far less than the millions of steps needed to journey a thousand miles. And mathematics, being abstract, has no physical constraints; one can always restart from scratch, try new avenues of attack, or backtrack at an instant’s notice. One does not always have these luxuries in other forms of problem-solving (e.g. trying to go home if you are lost).
Examples in number theory
Authors: Tao Terence 
Published: November 2023

Abstract
Number theory may not neccesarily be divine, but it still has an aura of mystique about it. Unlike algebra, which has as its backbone the laws of manipulating equations, number theory seems to derive its results from a source unknown. Take, for example, Lagrange’s theorem (first conjectured by Fermat) that every positive integer is a sum of four perfect squares (e.g. 30 42 32 22 12). Algebraically, we are talking about an extremely simple equation: but because we are restricted to the integers, the rules of algebra fail.
Minimal models
Authors: Félix Yves , Oprea John , Tanré Daniel 
Published: November 2023

Abstract
A minimal model is a particularly tractable kind of commutative differential graded algebra (cdga) that can be associated to any nice cdga or to any nice space. The word “minimal” emphasizes that, at least in many cases of interest, the model is calculable. The amazing feature of minimal models of spaces is their ability to algebraically encode all rational homotopy information about a space. This is, of course, why minimal models are important. This chapter includes definitions and the main properties of algebraic notions related to minimal models.
Geodesics
Authors: Félix Yves , Oprea John , Tanré Daniel 
Published: November 2023

Abstract
Let M be a smooth Riemannian manifold. The Riemannian structure of the manifold is reflected in the form its geodesics take. For instance, we see the symmetry of the sphere S 2 (with the Riemannian structure induced from R3) in the great circles that are its geodesics. Moreover, while the differential geometric structure of a physical system is detected by geodesics (e.g. in general relativity), the actual physical nature of such a system is seen in its motions. A beautiful result of Jacobi (see [216, Chapter 8] for instance) says that the Riemannian metric on the manifold of interest may be modified in a simple way so that the geometric and physical viewpoints agree; namely, the motions of the system are along geodesics with respect to the new metric.
Learning to Lobby the European Union: 20 Years of Change
Authors: Coen David , Richardson Jeremy 
Published: November 2023

Abstract
It is universally accepted that there has been a huge growth in European Union (EU) lobbying, at the EU and national levels, over the past two decades. There is now a dense EU interest group system and a concurrent explosion of EU interest groups studies (Mazey and Richardson 1993; Kohler-Koch and Eising 1999; Coen 2007; Beyer et al. 2008). However, while much progress has been made in collating interest group populations (Butt Philip 1989; Greenwood 1997, 2005; Berkhout and Lowery 2008), discussing mobilization strategies (Coen 1998; Beyers 2002; Eising 2004), and identifying access criteria to institutions (Bouwen 2002; Broscheid and Coen 2003), few studies have explained the full ‘EU lobbying footprint’ in a multilevel and institutional environment. This volume seeks to understand the role of interest groups in the policy process from agenda-setting to implementation.
Plane Autonomous Systems And Linearization
Authors: Jordan D W , Smith P 
Published: November 2023

Abstract
Chapter 1 describes the application of phase-plane methods to the equation x f (x, x) through the equivalent first-order system x y, y f (x, y). This approach permits a useful line of argument based on a mechanical interpretation of the original equation. Frequently, however, the appropriate formulation of mechanical, biological, and geometrical problems is not through a second-order equation at all, but directly as a more general type of first-order system of the form x X(x, y), y Y (x, y). The appearance of these equations is an invitation to construct a phase plane with x, y coordinates in which solutions are represented by curves
Perturbation Methods
Authors: Jordan D W , Smith P 
Published: November 2023

Abstract
This chapter describes techniques for obtaining approximations to periodic time solutions of nearly linear second-order differential equations subject to a harmonic forcing term, and to limit cycles of autonomous equations. The approximations take the form of an expansion in integer powers of a small parameter, having coefficients that are functions of time. There is some freedom in assigning the time-dependent coefficients; this is utilized to produce uniformly valid approximations under different circumstances, depending on the values of the main parameters of the equation. It is also shown how a homo-clinic path can be approximated by using similar methods. The processes reveal physical features having no analogue in linear theory, despite the fact that the equations considered have small nonlinearities.
The Beak of the Finch
Authors: Cronbach Lee 
Published: November 2023

Abstract
The finches of the Galápagos Islands are justifiably famous for inspiring Darwin’s theorizing about evolution. There are some nineteen sizable islands and dozens of smaller islets in the Galápagos archipelago. Each one has a slightly different flora, and therefore each presents a slightly different challenge for a small bird in search of dinner. What Darwin noticed in his time on the Galápagos was that the finches on different islands had slightly different beaks. Where there were large seeds to be cracked, beaks were thick and powerful. Where there were holes to be explored, beaks were thin and slender. Darwin’s explanation was that although the finches had all descended from a common ancestor, those
Wanderers
Authors: Nettle Daniel 
Published: November 2023

Abstract
Erica, at 55, is living a quiet life. Her pretty cottage in the downland of southern England stands in a little wooded valley, where, she tells me, deer and rabbits are her neighbours. At around 8am, she drives her little hatchback ten miles up the road to an office in another out-of-town location, which she shares with a couple of other journalists who work with her on her small magazine. She gets on well with her colleagues, but after work, her day is quiet; she drives back, with no rush-hour traffic to worry about, makes dinner, watches some television, and goes early to her bed, where she has, as she puts it ‘vivid, entertaining, cinematic and revealing dreams’.
Worriers
Authors: Nettle Daniel 
Published: November 2023

Abstract
Some people seem to get all the bad luck. Susan seems to have hit on a seam of bad men. As her high-school years in a London suburb drew to a close, she was pondering what to do with her life next. The teachers thought she was good enough—the brightest they had ever taught, in fact—to try the competitive entrance examination for Oxford University. However, not only would she not do this, but she would not even put in an application for a second-tier, or any other, university instead. She had a notion she would apply to Art School, but after making a fact-finding visit, she found the rate of attrition from the course too worrying.
Empathizers
Authors: Nettle Daniel 
Published: November 2023

Abstract
Suppose for a moment you have been lured into a laboratory by a psychologist. You are seated in a small cubicle, with a clear glass front. You are hungry. Just opposite you, the other side of a narrow corridor, is someone you know. He looks like he is in the same boat as you. In front of you are two levers. One of them, you have worked out, will bring a tray that is currently out of reach into your reach though a gap in the glass wall. On that tray is a glass of chilled water and something nice to eat. The second lever will also bring your tray into your reach, and additionally cause a similar tray to be moved into the reach of the man opposite.
Geometrical aspects of plane autonomous systems
Authors: Jordan D W , Smith P 
Published: November 2023

Abstract
3.1. (a) Surround the equilibrium point by a closed curve r (see Figure 3.1). Take any point P on r, and draw a vector S at P tangential to the phase path at P . Let Φ be the angle between a fixed direction and S measured counterclockwise as shown. As P makes one counter clockwise circuit of r, determine how the angle Φ changes as the direction of S changes. Any change will be a multiple of 2π . In this example Φ returns to its original value. Hence the index I 0.
Periodic solutions; averaging methods
Authors: Jordan D W , Smith P 
Published: November 2023

Abstract
The system (i) has one equilibrium point at the origin. From (ii) it can be seen that r = 1 is a phase path representing a periodic solution taken in the clockwise sense since θ˙ is negative. The path is a stable limit cycle since r &gt; 0 for r &lt; 1 and r &lt; 0 for r &gt; 1. The polar equations for the phase paths can be obtained by integrating which is the same equation as in (i). Therefore the phase diagram is the same as that shown in Figure 4.1 except that the direction of the phase paths is reversed.
Singular perturbation methods
Authors: Jordan D W , Smith P 
Published: November 2023

Abstract
How does the period obtained by the method of Problem 6.1 compare with that derived in Problem 1.34? In Problem 6.1 the initial condition given is x(0) = 1. This can be changed to a by the substitution of x = X/a into the differential equation in Problem 6.1, so that 6.3 Apply the method of Problem 6.1 to the equation ¨x +x = εx3+ε2αx5 with x(ε, 0) = 1,˙ x(ε, 0) = 0. Obtain the period to order ε3, and confirm that the period is correct for the pendulum when the right-hand side is the first two terms in the expansion of x − sin x. (Compare the result of Problem 1.33. To obtain the required equations simply add the appropriate term to the right-hand side of the equation for x2 in Example 6.1 in NODE.)
Liapunov methods for determining stability of the zero solution
Authors: Jordan D W , Smith P 
Published: November 2023

Abstract
10.1. In each case the origin is an equilibrium point of the autonomous system. where A, B and C (all different) are the principal moments of inertia, and (ω1, ω2, ω3) is the spin of the body in principal axes fixed in the body. Find all the states of steady spin of the body. is a Liapunov function for the case when A is the largest moment of inertia, so that this state is stable. Suggest a Liapunov function which will establish the stability of the case in which A is the smallest moment of inertia. Are these states asymptotically stable? Why would you expect V as given above to be a first integral of the Euler equations? Show that each of the terms in braces is such an integral Since ˙ V =0, then the level curves of V coincide with the solutions of the Euler equations. One conclusion is that the equilibrium states are not asymptotically stable. The second conclusion is that V must be composed of first integrals of the Euler equations in some manner.
Bifurcations and manifolds
Authors: Jordan D W , Smith P 
Published: November 2023

Abstract
The solutions are real for λ 3 and λ 1, and complex for 3 &lt; λ &lt; 1. The graphs of Re(m1) and Re(m2) against λ are shown in Figure 12.1. Noting the signs of m1 and m2, we can observe that the equilibrium point at the origin is: A bifurcation occurs at the parametric value λ 1 where, as λ increases, the equilibrium point changes from a stable node to an unstable saddle point. A homoclinic path (NODE, Section 3.6) is a phase path which joins an equilibrium point to itself in an autonomous system. Show that ˙x = y, ˙y = x − x2 has such a path and find its equation. Sketch the phase paths for the perturbed system ˙x = y+λx, ˙y = x−x2, for both λ &gt; 0 and λ &lt; 0. (The homoclinic saddle connection is destroyed by the perturbation; the system undergoes what is known as a homoclinic bifurcation (Section 3.6) at λ = 0.)
Geometric Mechanics and Symmetry
Authors: Holm Darryl D , Schmah Tanya , Stoica Cristina , Ellis David C P 
Published: November 2023

Abstract
Classical mechanics, one of the oldest branches of science, has undergone a long evolution, developing hand in hand with many areas of mathematics, including calculus, differential geometry, and the theory of Lie groups and Lie algebras. The modern formulations of Lagrangian and Hamiltonian mechanics, in the coordinate-free language of differential geometry, are elegant and general. They provide a unifying framework for many seemingly disparate physical systems, such as n-particle systems, rigid bodies, fluids and other continua, and electromagnetic and quantum systems. Geometric Mechanics and Symmetry is a friendly and fast-paced introduction to the geometric approach to classical mechanics, suitable for a one- or two- semester course for beginning graduate students or advanced undergraduates. It fills a gap between traditional classical mechanics texts and advanced modern mathematical treatments of the subject. After a summary of the necessary elements of calculus on smooth manifolds and basic Lie group theory, the main body of the text considers how symmetry reduction of Hamilton's principle allows one to derive and analyze the Euler-Poincaré equations for dynamics on Lie groups. Additional topics deal with rigid and pseudo-rigid bodies, the heavy top, shallow water waves, geophysical fluid dynamics and computational anatomy. The text ends with a discussion of the semidirect-product Euler-Poincaré reduction theorem for ideal fluid dynamics. A variety of examples and figures illustrate the material, while the many exercises, both solved and unsolved, make the book a valuable class text.
Bayesian Nonparametric Latent Feature Models
Authors: Ghahramani Zoubin , Griffiths Thomas L , Sollich Peter 
Published: November 2023

Abstract
We describe a flexible nonparametric approach to latent variable modelling in which the number of latent variables is unbounded. This approach is based on a probability distribution over equivalence classes of binary matrices with a finite number of rows, corresponding to the data points, and an unbounded number of columns, corresponding to the latent variables. Each data point can be associated with a subset of the possible latent variables, which we refer to as the latent features of that data point. The binary variables in the matrix indicate which latent feature is possessed by which data point, and there is a potentially infinite array of features. We derive the distribution over unbounded binary matrices by taking the limit of a distribution over N × K binary matrices as K → ∞ . We define a simple generative processes for this distribution which we call the Indian buffet process (IBP; Griffiths and Ghahramani, 2005, 2006) by analogy to the Chinese restaurant process (Aldous, 1985; Pitman, 2002). The IBP has a single hyperparameter which controls both the number of feature per object and the total number of features. We describe a two-parameter generalization of the IBP which has additional flexibility, independently controlling the number of features per object and the total number of features in the matrix. The use of this distribution as a prior in an infinite latent feature model is illustrated, and Markov chain Monte Carlo algorithms for inference are described.
Detecting Selection in DNA Sequences: Bayesian Modelling and Inference
Authors: Merl Daniel , Prado Raquel 
Published: November 2023

Abstract
Recent developments in Bayesian modelling of DNA sequence data for detecting natural selection at the amino acid level are presented. This article summarizes and discusses empirical model-based approaches. Key features of the modelling framework include the incorporation of biologically meaningful information via structured priors, posterior detection of sites under selection, and model validation via posterior predictive checks and/or estimation of gene and species trees. In addition, model selection is handled using a minimum posterior predictive loss criterion. The models presented here can incorporate relevant covariates such as amino acid properties, extending in this way previous approaches. Applications include the analysis of two DNA sequence alignments with different characteristics in terms of evolutionary divergences among the sequences: an abalone sperm lysin alignment with a strong underlying phylogenetic structure and a low divergence sequence alignment encoding the Apical Membrane Antigen-1 (AMA-1) in the P. falciparum human malaria parasite.
Comparing Normal Means: New Methods for an Old Problem*
Authors: Bernardo José M , Pérez Sergio 
Published: November 2023

Abstract
Comparing the means of two normal populations is a very old problem in mathematical statistics, but there is still no consensus about its most appropriate solution. In this paper we treat the problem of comparing two normal means as a Bayesian decision problem with only two alternatives: either to accept the hypothesis that the two means are equal, or to conclude that the observed data are, under the assumed model, incompatible with that hypothesis. The combined use of an information-theory based loss function, the intrinsic discrepancy (Bernardo and Rueda, 2002), and an objective prior function, the reference prior (Bernardo, 1979; Berger and Bernardo, 1992), produces a new solution to this old problem which, for the first time, has the invariance properties one should presumably require.
The Einstein-scalar field system
Authors: Rendall Alan D 
Published: November 2023

Abstract
The field theoretic matter model for which the most mathematical results are known for the Einstein-matter system is a massless linear scalar field solving the wave equation. The available results on this subject are surveyed in this chapter. This section is concerned with spherically symmetric solutions of the Einstein equations with vanishing cosmological constant coupled to a scalar field. This is the subject of a series of papers by Christodoulou whose motivation was to find a model for gravitational collapse which was as simple as possible.
Background Material
Authors: Joyce Dominic D 
Published: November 2023

Abstract
In this chapter we explain some background necessary for understanding the rest of the book. We shall assume that the reader is already familiar with the basic ideas of differential and Riemannian geometry (in particular, manifolds and submanifolds, tensors, and Riemannian metrics) and of algebraic topology (in particular, fundamental group, homology and cohomology). We start in 1.1 with a short introduction to exterior forms on manifolds, de Rham cohomology, and Hodge theory. These will be essential tools later in the book, and we discuss them out of completeness, and to fix notation.
Mirror Symmetry And The Syz Conjecture
Authors: Joyce Dominic D 
Published: November 2023

Abstract
Readers are warned that this is the most flawed and unsatisfactory chapter in the book, due partly to the incompetence of the author, and partly to the nature of the subject. String theory is a huge endeavour, and difficult for mathematicians to penetrate. Mirror symmetry is not a clean mathematical statement, but a swamp of complicated, continuously evolving conjectures, which are slowly being turned into theorems. Each field would take a book far longer than this to explain properly, such as Hori et al. [166] on mirror symmetry.
Hyperkähler And Quaternionic Kähler Manifolds
Authors: Joyce Dominic D 
Published: November 2023

Abstract
We begin in 10.1 with an introduction to hyperKähler geometry. Sections 10.2 and 10.3 describe examples of noncompact hyperKähler 4-manifolds, hyperKähler ALE spaces, and compact hyperKähler 4-manifolds, K3 surfaces. These are very well understood, by treating them as complex surfaces and using complex algebraic geometry, and we give a very precise description of the moduli space of hyperKähler structures on K3. Then 10.4 explains the theory of compact hyperKähler manifolds in higher dimensions. In comparison to Calabi–Yau manifolds, rather few examples are known.
Financing the Enlargement
Authors: Vassiliou George , Christoffersen Poul Skytte 
Published: November 2023

Abstract
Many generations of Europeans were dreaming to unite Europe; a dream that could not be realized as long as Europe was divided in two opposing blocs. In 1989 and 1990 the forceful division ended but huge social and economic differences remained between the ex-Warsaw Pact country members and the EU. Thus, the EU’s first task was to help the Central and Eastern European countries to overcome the neglect of many decades and promote the reform of their economies and civil society.
The Public’s Attitude to Enlargement
Authors: Vassiliou George 
Published: November 2023

Abstract
Generally speaking the prospect of EU enlargement from fifteen to twenty-five members was accepted by the EU public both in the fifteen member countries and the candidates as a fact. The issue did not create any great animosity but neither enthusiasm. From the moment the so-called Iron Curtain collapsed it was accepted as a sine que non that the EU would be enlarged. This feeling was strengthened with the incorporation of East Germany in the Federal Republic. From there on it was a matter of time as to when the various Central and Eastern European countries, in addition to Cyprus and Malta, would be invited to join. It is characteristic in this respect that during the whole period of the negotiations the media gave limited attention to the issues of enlargement while they pointed out various other issues with which the fifteen dealt at their summits.
Eradication of invasive species: progress and emerging issues in the 21st century
Authors: Parkes John P , Panetta F Dane 
Published: November 2023

Abstract
At an international conference on the eradication of invasive species, held in 2001, Simberloff (2002) noted some past successes in eradication—from the global eradication of smallpox (Fenner et al. 1988) to the many successful eradications of populations (mostly mammals) from small islands (e.g. Veitch and Bell 1990; Burbidge and Morris 2002). However, he cautioned that we needed to be more ambitious and aim higher if we are to prevent and reverse the growing threat of the homogenization of global biodiversity