1,721,009 research outputs found
Formally integrable complex structures on higher dimensional knot spaces
Get PDFLet S be a compact oriented finite dimensional manifold and M a finite dimensional Riemannian manifold, let Immf (S, M) the space of all free immersions phi : S -> M and let B-i(,f)+ (S, M) the quotient space Imm(f) (S, M)/Diff(+) (S), where Diff(+) (S) denotes the group of orientation preserving diffeomorphisms of S. In this paper we prove that if M admits a parallel r-fold vector cross product chi is an element of Omega(r) (M, TM) and dim S = r - 1 then B(i)(,f)(+)f (S, M) is a formally Kahler manifold. This generalizes Brylinski's, LeBrun's and Verbitsky's results for the case that S is a codimension 2 submanifold in M, and S = S-1 or M is a torsion-free G(2)-manifold respectively
Twisted Cohomotopy Implies Level Quantization of the Full 6d Wess-Zumino Term of the M5-Brane
Get PDFThe full 6d Hopf–Wess–Zumino term in the action functional for the M5-brane is anomalous as traditionally defined. What has been missing is a condition implying the higher analogue of level quantization familiar from the 2d Wess–Zumino term. We prove that the anomaly cancellation condition is implied by the hypothesis that the C-field is charge-quantized in twisted Cohomotopy theory. The proof follows by a twisted/parametrized generalization of the Hopf invariant, after identifying the full 6d Hopf–Wess–Zumino term with a twisted homotopy Whitehead integral formula, which we establish
Twisted Cohomotopy Implies M-Theory Anomaly Cancellation on 8-Manifolds
No full textWe consider the hypothesis that the C-field 4-flux and 7-flux forms in M-theory are in the image of the non-abelian Chern character map from the non-abelian generalized cohomology theory called J-twisted Cohomotopy theory. We prove for M2-brane backgrounds in M-theory on 8-manifolds that such charge quantization of the C-field in Cohomotopy theory implies a list of expected anomaly cancellation conditions, including: shifted C-field flux quantization and C-field tadpole cancellation, but also the DMW anomaly cancellation and the C-field’s integral equation of motion
Twisted cohomotopy implies twisted string structure on M5-branes
Get PDFWe show that charge-quantization of the M-theory C-field in J-twisted Cohomotopy implies the emergence of a higher Sp(1)-gauge field on single heterotic M5-branes, which exhibits a worldvolume Stringc2-structure
Higher T-duality of super M-branes
Get PDFWe establish a higher generalization of super L-infinity-algebraic T-duality of super WZW-terms for super p-branes. In particular, we demonstrate spherical T-duality of super M5-branes propagating on exceptional-geometric 11d super spacetime
Super-exceptional geometry: origin of heterotic M-theory and super-exceptional embedding construction of M5
Get PDFIn the quest for the mathematical formulation of M-theory, we consider three major open problems: a first-principles construction of the single (abelian) M5-brane Lagrangian density, the origin of the gauge field in heterotic M-theory, and the supersymmetric enhancement of exceptional M-geometry. By combining techniques from homotopy theory and from supergeometry to what we call super-exceptional geometry within super-homotopy theory, we present an elegant joint solution to all three problems. This leads to a unified description of the Nambu-Goto, Perry-Schwarz, and topological Yang-Mills Lagrangians in the topologically nontrivial setting. After explaining how charge quantization of the C-field in Cohomotopy reveals D’Auria-Fré’s “hidden supergroup” of 11d supergravity as the super-exceptional target space, in the sense of Bandos, for M5-brane sigma-models, we prove, in exceptional generalization of the doubly-supersymmetric super-embedding formalism, that a Perry-Schwarz-type Lagrangian for single (abelian) N = (1, 0) M5-branes emerges as the super-exceptional trivialization of the M5-brane cocycle along the super-exceptional embedding of the “half ” M5-brane locus, super-exceptionally compactified on the Hořava-Witten circle fiber. From inspection of the resulting 5d super Yang-Mills Lagrangian we find that the extra fermion field appearing in super-exceptional M-geometry, whose physical interpretation had remained open, is the M-theoretic avatar of the gaugino field
An exposition of the topological half of the Grothendieck-Hirzebruch-Riemann-Roch theorem in the fancy language of spectra
Get PDFWe give an informal exposition of pushforwards and orientations in
generalized cohomology theories in the language of spectra. The whole note can
be seen as an attempt at convincing the reader that Todd classes in
Grothendieck-Hirzebruch-Riemann-Roch type formulas are not Devil's appearances
but rather that things just go in the most natural possible way.Comment: 28 pages, 1 figure. Final version, to appear in Expositiones
Mathematicae (with English titles, despite the Latin name of the journal).
Exposition improved and additional material included, mostly in the first
part. An inaccuracy in Remark 3.6 fixe
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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