61,065 research outputs found
Traces and shards of self-injury: Strange accounting with “Author X”
No full textIn this strange account autoethnography, three or four authors explore their lived experiences with self-injury. Strange accounting is both a post-modern style of text, and a method for keeping identities concealed when risks and secrets are in play. Author X, a post-modern place-keeper for an anonymous author who may or may not have contributed to this manuscript, introduces a new dimension and layer of concealment. With Author X in-play and under erasure, the reader will never be sure if there were three or four authors on this manuscript. Through strange accounting, a post-structuralist/postmodernist frame will be applied to understanding the self-injury experience. We frame self-injury as a social practice and, for some, an everyday norm, while remaining acutely aware of the stigma surrounding the topic of self-injury. Each of us, coupled with Author X, provide the others cover to trace stories of self-injury through the literature, our flesh, and our lives
Multiple solutions for the non-Abelian Chern–Simons–Higgs vortex equations
No full textIn this paper we study the existence of multiple solutions for the non-Abelian Chem-Simons-Higgs (N x N)-system:Delta u(i) = lambda(Sigma(N)(j=1) Sigma(N)(k=1) K(kj)K(ji)e(uj)e(uk) - Sigma(N)(j=1) k(ji)e(uj)) + 4 pi Sigma(ni)(j=1) delta(pij), i=1, . . . , N;over a doubly periodic domain Omega, with coupling matrix K given by the Cartan matrix of SU(N + 1), (see (1.2) below). Here, lambda > 0 is the coupling parameter, delta(p )is the Dirac measure with pole at p and n(i) is an element of N, for i = 1,...,N. When N = 1, 2 many results are now available for the periodic solvability of such system and provide the existence of different classes of solutions known as: topological, non-topological, mixed and blow-up type. On the contrary for N >= 3, only recently in [27] the authors managed to obtain the existence of one doubly periodic solution via a minimization procedure, in the spirit of [46]. Our main contribution in this paper is to show (as in [46]) that actually the given system admits a second doubly periodic solutions of "Mountain-pass" type, provided that 3 <= N <= 5. Note that the existence of multiple solutions is relevant from the physical point of view. Indeed, it implies the co-existence of different non-Abelian Chem-Simons condensates sharing the same set (assigned component-wise) of vortex points, energy and fluxes. The main difficulty to overcome is to attain a "compactness" property encompassed by the so-called Palais-Smale condition for the corresponding "action" functional, whose validity remains still open for N >= 6. (C) 2019 Elsevier Masson SAS. All rights reserved
Scattering Amplitudes of Massive N=2 Gauge Theories in Three Dimensions
No full textWe study the scattering amplitudes of mass-deformed Chern-Simons theories and Yang-Mills-Chern-Simons theories with N=2 supersymmetry in three dimensions. In particular, we derive the on-shell supersymmetry algebras which underlie the scattering matrices of these theories. We then compute various 3 and 4-point on-shell tree-level amplitudes in these theories. For the mass-deformed Chern-Simons theory, odd-point amplitudes vanish and we find that all of the 4-point amplitudes can be encoded elegantly in superamplitudes. For the Yang-Mills-Chern-Simons theory, we obtain all of the 4-point tree-level amplitudes using a combination of perturbative techniques and algebraic constraints and we comment on difficulties related to computing amplitudes with external gauge fields using Feynman diagrams. Finally, we propose a BCFW recursion relation for mass-deformed theories in three dimensions and discuss the applicability of this proposal to mass-deformed N=2 theories
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A probabilistic assessment of sea level variations within the Last Interglacial stage
No full textThe Last Interglacial (LIG) stage (ca. 130–115 ka) provides a relatively recent example of a world with both poles characterized by greater-than- Holocene temperatures similar to those expected later in this century under a range of greenhouse gas emission scenarios. Previous analyses inferred that LIG mean global sea level (GSL) peaked 6–9 m higher than today (Kopp et al. 2009; Dutton & Lambeck 2012). Here, we extend our earlier work to perform a probabilistic assessment of sea level variability within the LIG highstand. Using the terminology for probability employed in the Intergovernmental Panel on Climate Change (IPCC) assessment reports, we find it extremely likely (95% probability) that the paleo-sea level record allows resolution of at least two intra-LIG sea level peaks and likely (67% probability) that the magnitude of low-to-high swings exceeded 4 m. Moreover, it is likely that there was a period during the LIG in which GSL rose at a 1000-year average rate exceeding 3 m/ky, but unlikely (33% probability) that the rate exceeded 7 m/ky and extremely unlikely (5% probability) that it exceeded 11 m/ky. These rate estimates can provide insight into rates of Greenland and/or Antarctic melt under climate conditions partially analogous to those expected in the twenty- first century.This is the authors’ preprint version of the manuscript: 23 January 2013. Originally submitted 18 September 2012. Accepted for publication in Geophysical Journal International, published by Oxford University Press.Peer reviewe
Doubly periodic self-dual vortices in a relativistic non-Abelian Chern–Simons model
No full textIn this paper we establish a multiplicity result concerning the existence of doubly periodic solutions in a 2 × 2 nonlinear elliptic system arising in the study of self-dual non-Abelian Chern-Simons vortices. We show that the system admits at least two solutions when the Chern-Simons coupling parameter ? >0 sufficiently large. As in Nolasco and Tarantello (Commun Math Phys 213:599-639, 2000), we use a variational formulation of the problem. Thus, we obtain a first solution via a constrained minimization method and show that it is asymptotically gauge-equivalent to the (broken) principal embedding vacuum of the system, as ? ? 0. Then we obtain a second solution by a min-max procedure of "mountain pass" type
A note on amplitudes in N=6 superconformal Chern-Simons theory
No full textThis is the accepted version of an article subsequently published in Journal of High Energy Physics July 2012, 2012:160. The original publication is available at www.springerlink.com http://link.springer.com/article/10.1007%2FJHEP07%282012%29160This version deposited to arXiv 30-07-12 arXiv:1205.6705v3 [hep-th
J. Simons, S. J. — Jerusalem, in the Old Testament. Researches a. Theories. (Studia Franc. Sholten memoriae dicata, I). Leiden, Brill, 1951
No full textX. J. Simons, S. J. — Jerusalem, in the Old Testament. Researches a. Theories. (Studia Franc. Sholten memoriae dicata, I). Leiden, Brill, 1951. In: Mélanges de l'Université Saint-Joseph, tome 31, 1954. pp. 389-390
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Kenau Simons Hasselaer
No full textMedium: engravingprints"Kenau Simons Hasselaer" [1995.2985.000.000], Houbraken, Jacobus, Unknown - UnknownArtist and Role: Houbraken, Jacobus, EngraverArtist and Role: Unknown - Unknown, ArtistExtent: sheet 16.8 x 10.
Relating U(N) x U(N) to SU(N) x SU(N) Chern-Simons membrane theories
No full textBy integrating out the U(1) B gauge field, we show that the U(n) x U(n) ABJM theory at level k is equivalent to a Z(k) identification of the (SU(n) x SU(n))/Z(n) Chern-Simons theory, but only when n and k are coprime. As a consequence, the k = 1 ABJM model for two M2-branes in R-8 can be identified with the N = 8 (SU(2)x SU(2))/Z(2) theory. We also conjecture that the U(2) x U(2) ABJM model at k = 2 is equivalent to the N = 8 SU(2) x SU(2)-theory
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