1,008 research outputs found

    Charges of Exceptionally Twisted Branes

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    The charges of the exceptionally twisted (D4 with triality and E6 with charge conjugation) D-branes of WZW models are determined from the microscopic/CFT point of view. The branes are labeled by twisted representations of the affine algebra, and their charge is determined to be the ground state multiplicity of the twisted representation. It is explicitly shown using Lie theory that the charge groups of these twisted branes are the same as those of the untwisted ones, confirming the macroscopic K-theoretic calculation. A key ingredient in our proof is that, surprisingly, the G2 and F4 Weyl dimensions see the simple currents of A2 and D4, respectively.Comment: 19 pages, 2 figures, LaTex2e, complete proofs of all statements, updated bibliograph

    On the Classification of Diagonal Coset Modular Invariants

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    We relate in a novel way the modular matrices of GKO diagonal cosets without fixed points to those of WZNW tensor products. Using this we classify all modular invariant partition functions of su(3)k⊕su(3)1/su(3)k+1su(3)_k\oplus su(3)_1/su(3)_{k+1} for all positive integer level kk, and su(2)k⊕su(2)ℓ/su(2)k+ℓsu(2)_k\oplus su(2)_\ell/su(2)_{k+\ell} for all kk and infinitely many ℓ\ell (in fact, for each kk a positive density of ℓ\ell). Of all these classifications, only that for su(2)k⊕su(2)1/su(2)k+1su(2)_k\oplus su(2)_1/su(2)_{k+1} had been known. Our lists include many new invariants.Comment: 24 pp (plain tex

    On the existence of Einstein oscillators and thermal conductivity in bulk metallic glass

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    Low-temperature specific heat and thermal conductivity of bulk metallic glasses are measured to identify the primary vibrational modes associated with their unique structures. An Einstein-type localized vibrational mode with an Einstein temperature of 112 K112K is found in bulk metallic glass Ni59.5Nb33.6Sn6.9Ni59.5Nb33.6Sn6.9. This localized vibrational mode causes resonant scattering of phonons and results in the localization of phonons which leaves the phonon hopping conduction the limiting mechanism of thermal transport in bulk metallic glass Ni59.5Nb33.6Sn6.9Ni59.5Nb33.6Sn6.9 at high temperature.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87816/2/031924_1.pd

    The phrase 'The Great War' in british discourse during world war one

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    The association of the term ‘The Great War’ with World War One, if it began 100 years ago, could be seen as telling, not only about attitudes at the time (and whether it meant ‘jolly big’ or ‘jolly good’), but about our retrospective attitudes to those who were involved. Through an examination of propaganda, periodicals, political statements and specific pre-war literature, an assumption that as a phrase it is indicative of jingoistic and bellicose hysteria generated by influential politicians for the gullible citizens of whichever participant nation, can be shown as a misleading simplification. Instead, with a concentration on Britain, a study of its use by statesmen such as Asquith and Lloyd George, the very particular circumstances under which it appeared in Punch magazine, and the overt zeal some advocates of war with Germany displayed from several years before 1914, is revealing of very different public standpoints among supporters of the war.info:eu-repo/semantics/publishedVersio

    On the complete classification of the unitary N=2 minimal superconformal field theories

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    Aiming at a complete classification of unitary N=2 minimal models (where the assumption of space-time supersymmetry has been dropped), it is shown that each modular invariant candidate of a partition function for such a theory is indeed the partition function of a minimal model. A family of models constructed via orbifoldings of either the diagonal model or of the space-time supersymmetric exceptional models demonstrates that there exists a unitary N=2 minimal model for every one of the allowed partition functions in the list obtained from Gannon's work. Kreuzer and Schellekens' conjecture that all simple current invariants can be obtained as orbifolds of the diagonal model, even when the extra assumption of higher-genus modular invariance is dropped, is confirmed in the case of the unitary N=2 minimal models by simple counting arguments.Comment: 53 pages; Latex; minor changes in v2: intro expanded, references added, typos corrected, footnote added on p31; renumbering of sections; main theorem reformulated for clarity, but contents unchanged. Minor revisions in v3: typos corrected, footnotes 5, 6 added, lemma 1 and section 3.3.2 rewritten for greater generality, section 3.3 review removed. To appear in Comm. Math. Phy

    Investigating the Information Systems Heterarchy

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    This article assesses how one IS organization is changing in response to the increased globalization of software development and posits the emergence of a new form of multi-national enterprise (MNE)—the heterarchy. Data from two projects create new insights into the structures and behaviors of ISMNEs as they adapt to global systems development. The article identifies four primary dimensions of impact—cultural, economic, operational, and organizational—and suggests how such organizations are evolvin
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