We summarize an explicit construction of a duality cycle for geometric transitions in type II and heterotic theories. We emphasize that the manifolds with torsion constructed with this duality cycle are crucial for understanding different phenomena appearing in effective field theories.

General Relativity assumes that spacetime is fully described by the metric alone. An alternative is the so called Palatini formalism where the metric and the connections are taken as independent quantities. The metric-affine theory of gravity has attracted considerable attention recently, since it was shown that within this framework some cosmological models, based on some generalized gravitati...

In a previous paper [4] we obtained the Hopf algebra structure of k*(G ; Q(P» where G is a compact connectvd Lie group and Q(P) is the quotient ring of Z with respect to a multiplicative subset generated by a set of primes, such that H*(G ; Q(P)) is torsion free . Here we study the properties of the connective K-theory of the Lie groups Spin(n) . Since H*(Spin(n) ; Z) is torsion free if n _< 6,...

The conformational properties of conjugated heteroaromatic bipyridines, pyridyl-pyridiniums and bipyridinium have been investigated using density functional theory (DFT). The molecules studied were neutral 2,20-bipyridine (2,20-bpy), 2,30bipyridine (2,30-bpy) and 3,30-bipyridine (3,30-bpy) and the singly protonated 3-pyridyl-20-pyridinium (3-py-20-pyH) and 2pyridyl-20-pyridinium (2-py-20-pyH) a...

PURPOSE The hypothesis of association between testicular torsion and hyperactive cremasteric reflex, worsened by cold weather, has not been proved. Thirteen studies in the literature evaluated this issue, with inconclusive results. The aim of the present study was to evaluate the seasonality of testicular torsion in a large subset of patients surgically treated in Brazil, and additionally to es...

On the basis of an algebraic relation between torsion and a classical spinor field a new interpretation of Einstein-Cartan gravity interacting with a classical spinor field is proposed. In this approach the spinor field becomes an auxiliary field and the dynamical equation for this field (the Heisenberg equation) is a dynamical, gravitational equation for torsion. The simplest version of this t...

Simplicial versions of topological abelian gauge theories are constructed which reproduce the continuum expressions for the partition function and Wilson expectation value of linked loops, expressible in terms of R–torsion and linking numbers respectively. The new feature which makes this possible is the introduction of simplicial fields (cochains) associated with the dual triangulation of the ...

The form of Maxwell’s theory is well known in the framework of general relativity, a fact that is related to the applicability of the principle of equivalence to electromagnetic phenomena. We pose the question whether this form changes if torsion and/or nonmetricity fields are allowed for in spacetime. Starting from the conservation laws of electric charge and magnetic flux, we recognize that t...

We extend some recent results on the differentiability of torsion theories. In particular, we generalize the concept of (α, β)-derivation to (α, β)higher derivation and demonstrate that a filter of a hereditary torsion theory that is invariant for α and β is (α, β)-higher derivation invariant. As a consequence, any higher derivation can be extended from a module to its module of quotients. Then...