Polytechnic University of Turin

About: Polytechnic University of Turin is a education organization based out in Turin, Piemonte, Italy. It is known for research contribution in the topics: Finite element method & Nonlinear system. The organization has 11553 authors who have published 41395 publications receiving 789320 citations. The organization is also known as: POLITO & Politecnico di Torino.

Magnetic charges in local field theory

Abstract: Novel lagrangians are discussed in which (non-abelian) electric and magnetic gauge fields appear on a par. To ensure that these lagrangians describe the correct number of degrees of freedom, tensor gauge fields are included with corresponding gauge symmetries. Non-abelian gauge symmetries that involve both the electric and the magnetic gauge fields can then be realized at the level of a single gauge invariant Lagrangian, without the need of performing duality transformations prior to introducing the gauge couplings. The approach adopted, which was initially developed for gaugings of maximal supergravity, is particularly suited for the study of flux compactifications

The maximal D = 4 supergravities

Abstract: All maximal supergravities in four space-time dimensions are presented. The ungauged Lagrangians can be encoded in an E_7(7)\Sp(56,R)/GL(28) matrix associated with the freedom of performing electric/magnetic duality transformations. The gauging is defined in terms of an embedding tensor which encodes the subgroup of E_7(7) that is realized as a local invariance. This embedding tensor may imply the presence of magnetic charges which require corresponding dual gauge fields. The latter can be incorporated by using a recently proposed formulation that involves tensor gauge fields in the adjoint representation of E_7(7). In this formulation the results take a universal form irrespective of the electric/magnetic duality basis. We present the general class of supersymmetric and gauge invariant Lagrangians and discuss a number of applications.

Two-port network analyzer calibration using an unknown 'thru'

Abstract: A procedure performed by using a genuine two-port reciprocal network instead of a standard 'thru' in a full two-port error correction of an automatic network analyzer is presented. Although it can be applied to any type of waveguide system, the proposed technique is particularly useful with noninsertable coaxial or one-wafer devices. Experimental comparisons show that the suggested procedure provides a great degree of accuracy. >