Non-perturbative aspects of gauge theories from gauge-gravity dualities

In this Ph.D. Thesis we consider two speci˝c supergravities which are well-established within the literature on holography, and which are known to provide the low-energy e˙ective description of either superstring theory or M-theory: the six-dimensional half-maximal theory of Romans, and the maximal supergravity in seven dimensions.We implement their dimensional reduction by compactifying on an S1 and T 2, respectively, to obtain a ˝ve-dimensional sigma-model coupled to grav-ity. Spectra of bosonic excitations are computed numerically by considering ˝eld ˛uctuations on background geometries which holographically realise con-˝nement. We furthermore propose a diagnostic tool to detect mixing e˙ects between scalar resonances and the pseudo-NambuGoldstone boson associated with spontaneous breaking of conformal invariance: the dilaton. This test con-sists of neglecting a certain component of the spin-0 ˛uctuation variables, ef-fectively disregarding their back-reaction on the underlying geometry; where discrepancies arise compared to the complete calculation we infer dilaton mix-ing. For both theories this analysis evinces a parametrically light dilaton.For each supergravity we uncover a tachyonic instability within their param-eter space; motivated by these pathological ˝ndings we proceed to conduct an investigation into their respective phase structures, reasoning that there must necessarily exist some mechanism by which these instabilities are rendered phys-ically inaccessible. We compile a comprehensive catalogue of geometrically dis-tinct backgrounds admissible within each theory, and derive general expressionsfor their holographically renormalised free energy F. Another numerical rou-tine is employed to systematically extract data for some special deformationparameters, and F is plotted in units of an appropriate universal scale.Our analysis proves fruitful: each theory exhibits clear evidence of a ˝rst-order phase transition which induces the spontaneous decompacti˝cation of the shrinking circular dimension before the instability manifests, favouring instead a class of singular solutions. The aforementioned dilaton resonance appears only along a metastable portion of the branch of con˝ning backgrounds

The Double Failure of 'Double Effect'

The ‘doctrine of double effect’ claims that it is in some sense morally less problematic to bring about a negatively evaluated state of affairs as a ‘side effect’ of one’s pursuit of another, morally unobjectionable aim than it is to bring it about in order to achieve that aim. In a first step, this chapter discusses the descriptive difference on which the claim is built. That difference is shown to derive from the attitudinal distinction between intention and ‘acceptance’, a distinction that is in turn claimed to ground in a feature of the decisions that generate the attitudes in question. The resulting analysis is then plugged into two different normative principles that may each be thought to specify the intuitions behind the doctrine of double effect, but which have frequently been conflated. The first concerns the permissibility of bringing about the merely accepted state of affairs, the second its reduced attributability. It is argued that examination of the intuitions behind the two principles supports neither version of the doctrine. Rather, the intuitions are best captured in an attribution principle based on subjective probabilities and a principle of attitude evaluation, neither of which make explicit reference to the attitude of intending

Dilatonic states near holographic phase transitions

The spectrum of bound states of special strongly coupled confining field theories might include a parametrically light dilaton, associated with the formation of enhanced condensates that break (approximate) scale invariance spontaneously. It has been suggested in the literature that such a state may arise in connection with the theory being close to the unitarity bound in holographic models. We extend these ideas to cases where the background geometry is non-AdS, and the gravity description of the dual confining field theory has a top-down origin in supergravity.We exemplify this programme by studying the circle compactification of Romans six-dimensional half-maximal supergravity. We uncover a rich space of solutions, many of which were previously unknown in the literature. We compute the bosonic spectrum of excitations, and identify a tachyonic instability in a region of parameter space for a class of regular background solutions. A tachyon only exists along an energetically disfavoured (unphysical) branch of solutions of the gravity theory; we find evidence of a first-order phase transition that separates this region of parameter space from the physical one. Along the physical branch of regular solutions, one of the lightest scalar particles is approximately a dilaton, and it is associated with a condensate in the underlying theory. Yet, because of the location of the phase transition, its mass is not parametrically small, and it is, coincidentally, the next-to-lightest scalar bound state, rather than the lightest one

Thematic Analysis: Human Rights and the 2010/11 U.K. Supreme Court

The efforts of the UK Supreme Court in the field of human rights during its first year reflected and informed a broader debate in society generally as to whether decisions of the European Court of Human Rights (hereafter EurCtHR ) in Strasbourg are appropriate for the domestic context. As the government mooted in Whitehall the merits of substituting the Human Rights Act 1998 (hereafter HRA ) with an autochthonous British Bill of Rights , the newly-formed Supreme Court in the old Middlesex Guildhall struggled to articulate a framework for why, when and how the rights guaranteed by the European Convention on Human Rights and Fundamental Freedoms (hereafter ECHR ), as incorporated into UK law by the HRA, might not mean for the British what Strasbourg says they mean for Europe

Introduction of Social Sciences in Australian Natural Resource Management Agencies

This paper examines the integration, from 1978 to 2002, of six social scientists in five Australian natural resource management agencies: CSIRO Australia, the Great Barrier Reef Marine Park Authority, the Murray Darling Basin Commission, the Western Australian Social Impact Unit, and the Queensland Social Impact Assessment Unit. All but one of the social scientists in the study occupied the first formal social science position in the respective agency. The organisational arrangements for integration, the roles of the social scientists and achievements of social science programs in those agencies illustrate a number of integration approaches and insights for effectively integrating social and natural science. Insights emanating from this research will be useful to inform future natural resource management that avoids integration failures. This paper illustrates both significant impediments to integration in practice and positive examples of integrated multidisciplinary approaches in natural resource management

Probing the holographic dilaton

Many strongly coupled field theories admit a spectrum of gauge-invariant bound states that includes scalar particles with the same quantum numbers as the vacuum. The challenge naturally arises of how to characterise them. In particular, how can a dilaton—the pseudo- Nambu-Goldstone boson associated with approximate scale invariance—be distinguished from other generic light scalars with the same quantum numbers? We address this problem within the context of gauge-gravity dualities, by analysing the fluctuations of the higher- dimensional gravitational theory. The diagnostic test that we propose consists of comparing the results of the complete calculation, performed by using gauge-invariant fluctuations in the bulk, with the results obtained in the probe approximation. While the former captures the mixing between scalar and metric degrees of freedom, the latter removes by hand the fluctuations that source the dilatation operator of the boundary field-theory. Hence, the probe approximation cannot capture a possible light dilaton, while it should fare well for other scalar particles.We test this idea on a number of holographic models, among which are some of the best known, complete gravity backgrounds constructed within the top-down approach to gauge-gravity dualities. We compute the spectra of scalar and tensor fluctuations, that are interpreted as bound states (glueballs) of the dual field theory, and we highlight those cases in which the probe approximation yields results close to the correct physical ones, as well as those cases where significant discrepancies emerge. We interpret the latter occurrence as an indication that identifying one of the lightest scalar states with the dilaton is legitimate, at least as a leading-order approximation

Coulomb branch of N=4 SYM and dilatonic scions in supergravity

We find a parametrically light dilaton in special confining theories in three dimensions. Their duals form what we call a scion of solutions to the supergravity associated with the large-N limit of the Coulomb branch of the N = 4 Super-Yang-Mills (SYM) theory. The supergravity description contains one scalar with bulk mass that saturates the Breitenlohner-Freedman unitarity bound. The new solutions are defined within supergravity, they break supersymmetry and scale invariance, and one dimension is compactified on a shrinking circle, yet they are completely regular. An approximate dilaton appears in the spectrum of background fluctuations (or composite states in the confining theory), and becomes parametrically light along a metastable portion of the scion of new supergravity solutions, in close proximity of a tachyonic instability. A first-order phase transition separates stable backgrounds, for which the approximate dilaton is not parametrically light, from metastable and unstable backgrounds, for which the dilaton becomes parametrically light, and eventually tachyonic

The genus- and family-group names of the Dytiscidae - additions and corrections (Coleoptera).

Eine frühere Revision der Gattungs- und Familiengruppennamen der Dytiscidae wird aktualisiert. Die Ergänzungen enthalten die in den vergangenen sechs Jahren beschriebenen Namen, und einige ältere, früher übersehene Namen, hauptsächlich von Gistel. Für Hydatoporus Gistel, Hyobius Gistel, Icmaleus Gistel, und Prosciastes Gistel werden Typusarten designiert. Actobaenidae Gistel wird als ein älteres subjektives Synonym von Hyphydrini Sharp erkannt. Die Konservierung von Hyphydrini wird empfohlen.Nomenklatorische HandlungenActobaenidae Gistel, 1856 (Dytiscidae), syn. n. of Hyphydrini SharpA previous review of genus- and family-group names of the water-beetle family Dytiscidae is updated. Additions include the names described within the last six years and some older, previously overlooked names, chiefly given by Gistel. Type species are designated for Hydatoporus Gistel, Hyobius Gistel, Icmaleus Gistel, and Prosciastes Gistel. Actobaenidae Gistel is considered a senior subjective synonym of Hyphydrini Sharp. Conservation of Hyphydrini is recommended. Nomenclatural ActsActobaenidae Gistel, 1856 (Dytiscidae), syn. n. of Hyphydrini Shar