Aspects of Group Field Theory

I review the basic ingredients of discretized gravity which motivate the introduction of Group Field Theory. Thus I describe the GFT formulation of some models and conclude with a few remarks on the emergence of noncommutative structures in such models.Comment: Invited Talk at the conference: XX Fall Workshop on Geometry and Physics, ICMAT, Madrid 2011. To be published in AIP Conference Proceeding

Temperature induced phase transitions in four fermion models in curved space-time

The large N limit of the Gross-Neveu model is here studied on manifolds with constant curvature, at zero and finite temperature. Using the zeta-function regularization, the phase structure is investigated for arbitrary values of the coupling constant. The critical surface where the second order phase transition takes place is analytically found for both the positive and negative curvature cases. For negative curvature, where the symmetry is always broken at zero temperature, the mass gap is calculated. The free energy density is evaluated at criticality and the zero curvature and zero temperature limits are discussed.Comment: Latex file, 24 pages, 3 eps figures. Minor corrections. To appear in Nucl. Phys.

Buildings or Festivals?

Marco Vitale ist wissenschaftlicher Mitarbeiter in Alter Geschichte (Epigraphie, Numismatik) in Basel und Zürich. Er wurde 2010 promoviert mit einer Untersuchung zur Verwaltung der hellenistischen und römischen Asia Minor (Eparchie und Koinon). Er veröffentlichte eine weitere Monografie zum antiken Syrien (Koinon Syrias). Seine jüngste Veröffentlichung, die Habilitationsschrift, erschien 2017 (Das Imperium in Wort und Bild)

A field-theoretic approach to Spin Foam models in Quantum Gravity

We present an introduction to Group Field Theory models, motivating them on the basis of their relationship with discretized BF models of gravity. We derive the Feynmann rules and compute quantum corrections in the coherent states basis.Comment: 16 pages, 3 figures. Proceedings of the Workshop on Non Commutative Field Theory and Gravity, September 8-12, 2010 Corfu Greec

The Contemporary EU's Notion of Territoriality and External Borders

The predominant spatial conception of the EU contributes to an evident emergence of a sharpened territorial building of the European space. By all evidence the idea of both the territorial cohesion and territorial continuity shows how relevant the notion of territoriality in the ‘European discourse’ is and consequently how accepted the instrument of hard and closed border and the sharp inside/outside dichotomy are. Due to this pragmatic notion of territoriality, the idea of the EU as a ‘non-Westphalian new empire’ (according to the ‘neo-medieval paradigm’) became at least unrealistic. Its borders are getting more territorial, physical and visible. Hard border policies and practices on the Eastern and Western Balkan borders mirror the existence of a de facto barrier and of a deep ‘Westphalian memory’ in the way of using the territory as support of political unity

Multivariate medians and measure-symmetrization

We discuss two research areas dealing respectively with (1) a class of multivariate medians and (2) a symmetrization algorithm for probability measures.Comment: Published at http://dx.doi.org/10.1214/074921707000000201 in the IMS Lecture Notes Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org