5,483 research outputs found
Modular transformations of admissible N = 2 and Affine sl(2|1;C) characters
No full textThis thesis is a study of the affine super-algebra sl(2|l; C) and N = 2 superconformal algebra at fractional levels. In the first chapter we review background material on Conformal Field Theory, and how it appears in the context of string theory and the Wess - Zumino – Novikov - Witten model. We also discuss integrable and admissible representations of infinite dimensional algebras and their modular transformations. In Chapter 2 we elaborate some more on modular transformations and we derive them in the case of non - unitary minimal N = 2 characters. Some very explicit formulas are presented. In Chapter 3 we discuss character formulas for the affine sl(2|l;C) algebra and some of their general properties are given, in particular their behaviour under spectral flow. In Chapter 4 we turn to the study of sumrules for sl(2|l;C) at level k. These involve the product of sl(2) characters at level k, k', and 1 with {k + l){k' + !) = 1. We consider k + 1 = for = 1, p e Z*, u eN and show that the sumruleswe have obtained agree with the literature when the parameter p is restricted to p = 1. We use the integral form of the sumrules to study the modular properties of sl(2|l) characters at fractional level in the last section of Chapter 4.The advisor for this work has been Dr. Anne Taormina
An exploratory study of shared leadership interactions in organisational teams
No full textThis research explores recent conceptions of leadership as a shared, reciprocal influence process. Contrary to traditional leader-centric approaches, such views suggest that leadership is performed collectively, particularly in team-based organisations. However, our understanding of how such approaches are put into practice is lacking, especially in the commercial domain. To bridge this gap, this study provides an in-depth, qualitative exploration of the interactions of team members in organisational settings, as they share in the leadership of their team. This was facilitated by the application of Social Exchange Theory as a theoretical foundation for the study, which enabled the research to focus on the mechanism through which shared leadership (SL) happens, i.e. social exchanges.The empirical insights presented have been gained through multiple case studies in professional organisations, involving semi-structured interviews and participant diaries. This fieldwork enabled the development of a framework depicting the exchange behaviours of those engaging in SL within their teams, providing a unique insight into the underlying dynamics of the SL process itself. Overall, the study provides strong support for the notion that leadership can be shared by multiple individuals, as SL emerged in all contexts studied. Significantly however, the pattern of SL was not the same in all contexts, and four distinct forms of SL are identified, including the specialisation in leadership behaviours, the rotation of leadership responsibilities, the simultaneous enactment of leadership and the centralisation of leadership activities. Contributing to an understanding of what is shared, the study reveals that SL permits a wide variety of leadership behaviours to be expressed.Key theoretical contributions include the framework of SL interactions (Fig. 7.6), illustrating how individuals make choices with regard to sharing in the leadership of their team; and the identification of different patterns of SL emerging from specific contextual and relational conditions. Practical contributions are derived from the identification of leadership behaviours that are amenable to sharing, providing an insight into how SL could be employed to increase the leadership capacity in team-based organisational settings
Admissible representations and characters of the affine superalgebras osp(l,2) and ŝl(2|l)
No full textIn this thesis we compute characters and supercharacters of irreducible admissible representations for the two affine superalgebras osp(l,2;C) and l(2|l;C).The work on osp(l, 2; C) includes a derivation of the embedding diagram. We compute the modular transformations of the Neveu-Schwarz characters of osp(l, 2; C) and show that they transform in a manner consistent with the different possible free fermion spin structures on a torus. In chapter 3 we turn our attention to ŝl(2|l;C). Characters and supercharacters are computed for three classes of admissible representation. We have to derive the embedding diagram for one of these classes. We show that the integrable characters in the classes we study are identical to characters of the N = 4 superconformal algebra and that some of the sl(2|l;C) characters have a pole in a certain limit. The residue at this pole is computed and it is found to be proportional to an N = 2 minimal character. Specialising to fractional levels k of the form k + 1 = l/u,u ϵ N, we consider the SL(2|1)/SL{2) coset theory and make a conjecture that it is a product of a parafermion theory and a rational torus model. The appearance of parafermion characters and rational torus model characters in the branching functions of some examples that we have worked out leads to a conjecture for the general form of the branching functions whenever the level k has the form k + 1 = 1/u.The modular T transformation can be worked out easily for any character or super- character we have computed. We work out the 5 transformation of the Neveu-Schwarz characters in two examples and find that we get a unitary S-matrix in each case. The thesis finishes with some interesting identities between ŝu(2) string functions which are a corollary of the work on branching functions
CR1 Knops blood group alleles are not associated with severe malaria in the Gambia
No full textThe Knops blood group antigen erythrocyte polymorphisms have been associated with reduced falciparum malaria-based in vitro rosette formation (putative malaria virulence factor). Having previously identified single-nucleotide polymorphisms (SNPs) in the human complement receptor 1 (CR1/CD35) gene underlying the Knops antithetical antigens Sl1/Sl2 and McC(a)/McC(b), we have now performed genotype comparisons to test associations between these two molecular variants and severe malaria in West African children living in the Gambia. While SNPs associated with Sl:2 and McC(b+) were equally distributed among malaria-infected children with severe malaria and control children not infected with malaria parasites, high allele frequencies for Sl 2 (0.800, 1,365/1,706) and McC(b) (0.385, 658/1706) were observed. Further, when compared to the Sl 1/McC(a) allele observed in all populations, the African Sl 2/McC(b) allele appears to have evolved as a result of positive selection (modified Nei-Gojobori test Ka-Ks/s.e.=1.77, P-valu
Quantum and its irreducible representations
No full textWe define for real a unital -algebra
quantizing the universal enveloping
-algebra of . The -algebra
is realized as a -subalgebra of the
Drinfeld double of and its dual Hopf -algebra
, generated by the equatorial Podle\'s sphere coideal
-subalgebra of and
its associated orthogonal coideal -subalgebra . We then classify all the irreducible
-representations of .Comment: 22 pages; author accepted manuscrip
Hecke algebras for inner forms of p-adic special linear groups
No full textContains fulltext :
176258.pdf (Publisher’s version ) (Open Access
On the sheaf-theoretic SL(2, C) Casson–Lin invariant
No full textWe prove that the (τ-weighted, sheaf-theoretic) SL(2, C) Casson–Lin invariant introduced by Manolescu and the first author is generically independent of the parameter τ and additive under connected sums of knots in integral homology 3-spheres. This addresses two questions asked by Manolescu and the first author. Our arguments involve a mix of topology and algebraic geometry, and rely crucially on the fact that the SL(2, C) Casson–Lin invariant admits an alternative interpretation via the theory of Behrend functions.</p
Candidatus Rhetoricae (or Novus Candidatus).
No full textThis little book is a find whatever it finally turns out to be! For now it seems to be a Jesuit collegium text in rhetoric following the Progymnasmata of Aphthonius. If one works from the back of the book, there is an apparently independent 48-page work, Angelus Pacis by Nicolas Caussini (Latinized name), S.J. The rest of the book seems to be a commentary on or presentation of Aphthonius' Progymnasmata in 3 parts covering 435 pages, followed by a T of C and an AI, which is often one page off. Pars II is titled Rhetoricae Praecepta, Pars III De Panegyrico seu Laudatione. Pars I seems to be Apparatus ad Fabulam et Narrationem. Fable is handled on 15-31. After the famous Greek definition of Theion done into Latin ( sermo falsus veritatem effingens ), the author distinguishes rational (human) and moral (animal) fables, with mixed fables including both. He holds (19) that the sense of the fable generally needs to be expressed; otherwise people often miss the point of a fable. His Latin for promythium is praefabulatio, for epimythium affabulatio. Apologus and parabola are identical for him with fabula. After describing the qualities and uses of fables, the author presents some nine fables that exemplify various levels of style, twice telling the same stories on two levels (WL and FC). The last example is of the florid style: The Silkworm and the Spider takes four pages to tell! I found this book sitting in a box of disparate, unmarked, old books. It pays to look!This is a hardbound book (hard cover)Language note: Bilingual: Greek/LatinElzevers
Searches for New Physics effects in b →sl-sl+ transitions
No full textThe dissertation aims at presenting the current situation in the measurements of electroweak
penguin diagrams dominated decays: b → sl−l+1 . These decays have been a smoking gun
for hunting for New Physics effects over many years, but in the last three years the research
on these phenomena has intensified due to new measurements. Enormous progress has
been made both on the theoretical and the experimental sides to understand the measured
deviations from the current Standard Model predictions, referred to in what follows as
“anomalies”. The author of this dissertation has been one of the main authors of the angular analysis
of B0→ K∗ 0µ+µ− decay in the LHCb experiment, which has been widely regarded as one
of the most important results of the flavour physics sector in recent years. He has proposed
a method called “the method of moments” to measure the angular terms of this decay,
which he has later successfully applied in the measurement itself. Moreover, he has been
the driving force behind the two other important analyses in LHCb: the measurement of
the angular distribution and branching ratio of the B0→ K∗ 0 (1430)µ+µ− decay, where again the method of moments has been used to obtain the angular coefficients, and the search for the light scalar particle that can be produced in the b → s transitions and that decays to a dimuon pair. In this case no signal has been observed and the upper limits on the branching fraction have been set, later to be used for constraining the inflaton model.
The dissertation is organized as follows: the brief introduction is followed by, the second
chapter devoted to a theoretical description of rare B decays, where the effective field
theory formalism is introduced. Furthermore, the author discusses the current theoretical
problems in calculating the Standard Model predictions for the b → sl−l+ processes. Last but not least, the optimised angular observables that are less dependent on the form
factors uncertainness are derived. The third chapter describes the experimental apparatus
used in the b → sl−l+ measurements. Special focus is put on the sub-detectors that play
an important role in the studies of b → sl−l+ transitions. Chapters 4, 5, 6 are devoted to
describing the data analyses performed by the author in the LHCb experiment. In Chapter 7
the global analysis of electroweak penguin decays is presented. This kind of global analysis
has become extremely popular in the past few years as it helps to constrain and pin down those New Physics models that are likely to be responsible for the observed anomalies. The
author of this monograph is involved in one of the biggest collaborations performing New
Physics fits, where he is the convenor of the Flavour Working group. Furthermore, the
author presents his own study on separating the long distance effects in the B0→ K∗ 0µ+µ−decay. This is the state of the art way of determining those contributions. The chapter ends with a description of possible New Physics models that can explain the observed discrepancies
contravariant function-valued valuations on polytopes
No full textWe present a complete classification of contravariant,
-valued valuations on polytopes, without any
additional assumptions.It extends the previous results of the second author
[Int. Math. Res. Not. 2020] which have a good connection with the and
Orlicz Brunn-Minkowski theory. Additionally, our results deduce a complete
classification of contravariant symmetric-tensor-valued
valuations on polytopes
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