3,986 research outputs found
Intersecting M2- and M5-branes
No full textIf an M2-brane intersects an M5-brane the canonical Wess-Zumino action is plagued by a Dirac-anomaly, i.e. a non-integer change of the action under a change of Dirac-brane. We show that this anomaly can be eliminated at the expense of a gravitational anomaly supported on the intersection manifold. Eventually we check that the last one is cancelled by the anomaly produced by the fermions present. This provides a quantum consistency check of these intersecting configurations
String κ-anomalies and D = 10 supergravity constraints: the solution of a puzzle
No full textThe κ-anomaly cancellation mechanism in the heterotic superstring determines the superspace constraints for N = 1, D = 10 Supergravity-Super-Yang-Mills theory. We point out that the constraints found recently in this way appear to disagree with superspace solutions found in the past. We solve this puzzle establishing perfect agreement between the two methods. © 1995
Quantum properties of the heterotic five-brane
No full textWe find that the conjectured heterotic SO(32) five-brane sigma model develops necessarily k-anomalies, and we investigate their form. We show that these anomalies can be absorbed by modifications of the superspace constraints, that satisfy automatically the modified Bianchi-identity of N=1, D=10 supergravity. The k-anomalies induce in particular a quantum deformation of the torsion constraint
51. Lechner (K.). Hellenen und Barbaren im Weltbild der Byzantiner. Die alten Bezeichnungen als Ausdruck eines neuen Kulturbewustseins. Diss. München, 1954
No full textGuilland Rodolphe. 51. Lechner (K.). Hellenen und Barbaren im Weltbild der Byzantiner. Die alten Bezeichnungen als Ausdruck eines neuen Kulturbewustseins. Diss. München, 1954. In: Revue des Études Grecques, tome 69, fascicule 324-325, Janvier-juin 1956. pp. 257-258
Plumbing, electricity, acoustics : sustainable design methods for architecture / Norbert Lechner.
No full textIncludes index.xi, 289 pages :Discover sustainable methods for designing crucial building systems for architects.
This indispensable companion to Norbert Lechner's landmark volume Heating, Cooling, Lighting: Sustainable Design Methods for Architects, Third Edition completes the author's mission to coverall topics in the field of sustainable environmental control. It provides knowledge appropriate for the level of complexity needed at the schematic design stage and presents the most up-to-date information available in a concise, logical, accessible manner and arrangement. Although sustainability deals with many issues, those concerning energy and efficiency are the most critical, making an additional goal of this book one of providing architects with the skills and knowledge needed to create buildings that use electricity and water efficiently. Guidelines and rules-of-thumb are provided to help designers make their buildings use less energy, less water, and less of everything else to achieve their primary objectives.
In addition, this book:
Addresses ways to reduce electricity usage through more efficient lighting systems and appliances and by incorporating automatic switches and control systems that turn off systems not in use.
Covers the design of well-planned effluent treatment systems that protect against potential health hazards while also becoming a valuable source of reclaimed water and fertilizer
Provides coverage of fire protection and conveyance systems, including very efficient types of elevators and escalators and designs that encourage the use of stairs or ramps.
Complete with case studies that illustrate how these systems are incorporated into large-project plans, Plumbing, Electricity, Acoustics is an indispensable resource for any architect involved in a sustainable design project
ModMax meets Susy
No full textWe give a prescription for N = 1 supersymmetrization of any (four-dimensional) nonlinear electrodynamics theory with a Lagrangian density satisfying a convexity condition that we relate to semi-classical unitarity. We apply it to the one-parameter ModMax extension of Maxwell electrodynamics that preserves both electromagnetic duality and conformal invariance, and its Born-Infeld-like generalization, proving that duality invariance is preserved. We also establish superconformal invariance of the superModMax theory by showing that its coupling to supergravity is super-Weyl invariant. The higher-derivative photino-field interactions that appear in any supersymmetric nonlinear electrodynamics theory are removed by an invertible nonlinear superfield redefinition
On p-form gauge theories and their conformal limits
No full textRelations between the various formulations of nonlinear p-form electrodynamics with conformal-invariant weak-field and strong-field limits are clarified, with a focus on duality invariant (2n − 1)-form electrodynamics and chiral 2n-form electrodynamics in Minkowski spacetime of dimension D = 4n and D = 4n + 2, respectively. We exhibit a new family of chiral 2-form electrodynamics in D = 6 for which these limits exhaust the possibilities for conformal invariance; the weak-field limit is related by dimensional reduction to the recently discovered ModMax generalisation of Maxwell’s equations. For n > 1 we show that the chiral ‘strong-field’ 2n-form electrodynamics is related by dimensional reduction to a new Sl(2; R)-duality invariant theory of (2n − 1)-form electrodynamics
Nonlinear duality-invariant conformal extension of Maxwell's equations
No full textAll nonlinear extensions of the source-free Maxwell equations preserving both SO(2) electromagnetic duality invariance and conformal invariance are found, and shown to be limits of a one-parameter generalization of Born-Infeld electrodynamics. The strong-field limit is the same as that found by Bialynicki-Birula from Born-Infeld theory but the weak-field limit is a new one-parameter extension of Maxwell electrodynamics, which is interacting but admits exact light-velocity plane-wave solutions of arbitrary polarization. Small-amplitude waves on a constant uniform electromagnetic background exhibit birefringence, but one polarization mode remains lightlike
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