On the chiral perturbation theory for two-flavor two-color QCD at finite chemical potential

We construct the chiral perturbation theory for two-color QCD with two quark flavors as an effective theory on the SO(6)/SO(5) coset space. This formulation turns out to be particularly useful for extracting the physical content of the theory when finite baryon and isospin chemical potentials are introduced, and Bose--Einstein condensation sets on.Comment: 10 pages, 1 eps figure, to be published in Mod. Phys. Lett.

O(n,n) invariance and Wald entropy formula in the Heterotic Superstring effective action at first order in alpha'

We perform the toroidal compactification of the full Bergshoeff-de Roo version of the Heterotic Superstring effective action to first orderin $\alpha'$. The dimensionally-reduced action is given in a manifestly-O(n,n)-invariant form which we use to derive a manifestly-O(n,n)-invariant Wald entropy formula which we then use to compute the entropy of $\alpha'$-corrected, 4-dimensional, 4-charge, static, extremal, supersymmetric black holes.Comment: References and comments added. Version to be published in Journal of High Energy Physic

Extending the isolated horizon phase space to string-inspired gravity models

An isolated horizon (IH) is a null hypersurface at which the geometry is held fixed. This generalizes the notion of an event horizon so that the black hole is an object that is in local equilibrium with its (possibly) dynamic environment. The first law of IH mechanics that arises from the framework relates quantities that are all defined at the horizon. IHs have been extensively studied in Einstein gravity with various matter couplings and rotation, and in asymptotically flat and asymptotically anti-de Sitter (ADS) spacetimes in all dimensions $D\geq3$. Motivated by the nonuniqueness of black holes in higher dimensions and by the black-hole/string correspondence principle, we devote this thesis to the extension of the framework to include IHs in string-inspired gravity models, specifically to Einstein-Maxwell-Chern-Simons (EMCS) theory and to Einstein-Gauss-Bonnet (EGB) theory in higher dimensions. The focus is on determining the generic features of black holes that are solutions to the field equations of the theories under consideration. We obtain various results for non-extremal, extremal and supersymmetric IHs in EM-CS theory, and for non-rotating IHs in EGB theory. (An extended abstract is given in the PDF file.)Comment: Ph.D dissertation; Memorial University of Newfoundland; 63 pages; 1 figure; v2: typos correcte