An so(4,C)-covariant hamiltonian formulation of a family of generalized Hilbert– Palatini actions depending on a parameter (the so called Immirzi parameter) is developed. It encompasses the… (More)

We use the manifestly Lorentz covariant canonical formalism to evaluate eigenvalues of the area operator acting on Wilson lines. To this end we modify the standard definition of the loop states to… (More)

An so(4,C)-covariant hamiltonian formulation of a family of generalized Hilbert– Palatini actions depending on a parameter (the so called Immirzi parameter) is developed. It encompasses the… (More)

We suggest a modification of the Barrett-Crane spin foam model of 4-dimensional Lorentzian general relativity motivated by the canonical quantization. The starting point is Lorentz covariant loop… (More)

Covariant loop gravity comes out of the canonical analysis of the Palatini action and the use of the Dirac brackets arising from dealing with the second class constraints (“simplicity” constraints).… (More)

We argue that the origin of non-perturbative corrections e−2πRnμ in the c = 1 matrix model is (1, n) D-branes of Zamolodchikovs. We confirm this identification comparing the flow of these corrections… (More)

We study general linear perturbations of a class of 4d real-dimensional hyperkähler manifolds obtainable by the (generalized) Legendre transform method. Using twistor methods, we show that… (More)

We revise imposition of various constraints in spin foam models of 4-dimensional general relativity. We argue that the usual simplicity constraint must be supplemented by a constraint on holonomies… (More)

We present some results on instanton corrections to the hypermultiplet moduli space in Calabi-Yau compactifications of Type II string theories. Previously, using twistor methods, only a class of… (More)

We consider non-chiral, full Lorentz group-based Plebanski formulation of general relativity in its version that utilizes the Lagrange multiplier field Φ with “internal” indices. The Hamiltonian… (More)