Mercedes Martin-Benito

Research Interests

LOOP QUANTUM COSMOLOGY (LQC)

LQC deals with the canonical quantization of symmetry reduced models for general relativity, cosmological models for instance, adapting the techniques of loop quantum gravity to the reduced model under consideration. The main goal of this approach is to get a resolution of the classical singularities at the quantum level, by means of the quantum corrections coming from the geometry. This quantization program has been developed quite successfully in the case of homogeneous models. My main interest in this field of research is the extension of the LQC program to inhomogeneous models (midisuperspaces), such as Gowdy cosmologies.


SPINFOAM COSMOLOGY

Spinfoams, the covariant framework for loop quantum gravity, attempt to provide a discrete (and regularized) path integral formalism for quantum gravity. They provide transition amplitudes between quantum states of geometry (spin-network states). Spinfoam cosmology deals with the investigation of simple spinfoam configurations, as an attempt to model with them symmetry reduced models for general relativity, such as cosmological models. At this respect, I am not only interested in the possibility of actually being able to model cosmology using the spinfoam dynamics, but also in using these simple spinfoam configurations to understand the link between the covariant and the canonical dynamics.


COARSE-GRAINING OF TOY SPINFOAM MODELS

In order to confirm whether spinfoam models really provide a theory for quantum gravity, it is essential to investigate their continuum limit and check that it is in agreement with general relativity. One way to do this is to analyze their renormalization flow under coarse-graining. This task is highly complicated, mainly due to the fact that spinfam models for quantum gravity are based on Lie groups. As a starting point to go in this direction, one can define toy models based on finite groups still capturing, up to some extend, most of the main features of the full spinfoam models. These models provide a manageable arena to analyze the phase transition from the discrete to the continuum.

Positions Held

• May 2012 - Present: Perimeter Institute for Theoretical Physics, Postdoctoral Researcher
• Nov 2010 - Apr 2012: Albert-Einstein-Institute (Golm,Germany), Postdoctoral Researcher
• Oct 2006 - Oct 2010: Institute of Structure of the Matter - CSIC (Madrid, Spain), PhD Student

Awards

• Spanish National Research Council PhD fellowship

Recent Publications

• E.R. Livine, M. Martín-Benito, Group theoretical Quantization of Isotropic Loop Cosmology, Phys. Rev. D, 85, 2012, 124052, arxiv: /prd.aps.org/abstract/PRD/v85/i12/e124052
• B. Dittrich, F.C. Eckert, M. Martin-Benito, Coarse graining methods for spin net and spin foam models, New J.Phys., 14, 2012, 035008, arxiv: /dx.doi.org/10.1088/1367-2630/14/3/035008
• M. Martin-Benito, D. Martin-de Blas, G.A. Mena Marugan, Matter in inhomogeneous loop quantum cosmology: the Gowdy T3 model, Phys.Rev. D, 83, 2011, 084050, arxiv: /dx.doi.org/10.1103/PhysRevD.83.084050
• M. Martin-Benito, G.A.Mena Marugan, E. Wilson-Ewing, Hybrid Quantization: From Bianchi I to the Gowdy Model, Phys.Rev. D, 82, 2010, 084012, arxiv: /dx.doi.org/10.1103/PhysRevD.82.084012
• L.J. Garay, M. Martin-Benito, G.A. Mena Marugan, Inhomogeneous Loop Quantum Cosmology: Hybrid Quantization of the Gowdy Model, Phys.Rev. D, 82, 2010, 044048, arxiv: /dx.doi.org/10.1103/PhysRevD.82.044048
• M, Martin-Benito, G.A.Mena Marugan, J. Olmedo, Further Improvements in the Understanding of Isotropic Loop Quantum Cosmology, Phys.Rev. D, 80, 2009, 104015, arxiv: /dx.doi.org/10.1103/PhysRevD.80.104015
• G.A. Mena Marugan, M. Martin-Benito, Hybrid Quantum Cosmology: Combining Loop and Fock Quantizations, Int.J.Mod.Phys. A, 24, 2009, 2820-2838, arxiv: /dx.doi.org/10.1142/S0217751X09046187
• M. Martin-Benito, G.A.Mena Marugan, T. Pawlowski, Physical evolution in Loop Quantum Cosmology: The Example of vacuum Bianchi I, Phys.Rev. D, 80, 2009, 084038, arxiv: /dx.doi.org/10.1103/PhysRevD.80.084038
• M. Martin-Benito, L. J. Garay, G.A. Mena Marugan, Hybrid Quantum Gowdy Cosmology: Combining Loop and Fock Quantizations, Phys.Rev. D, 78, 2008, 083516, arxiv: /prd.aps.org/abstract/PRD/v78/i8/e083516
• M. Martin-Benito, G.A. Mena Marugan, T. Pawlowski, Loop Quantization of Vacuum Bianchi I Cosmology, Phys.Rev. D, 78, 2008, 064008, arxiv: /prd.aps.org/abstract/PRD/v78/i6/e064008
• Classical Setting and Effective Dynamics for Spinfoam Cosmology, E.R. Livine, M. Martin-Benito, arxiv: 1111.2867 http://arxiv.org/abs/arxiv: 1111.2867
• Cosmologia Cuantica de Lazos: Anisotropias e Inhomogeneidades, M. Martin-Benito, arxiv: 1109.5618 http://arxiv.org/abs/arxiv: 1109.5618

Seminars

• Introduction to Loop Quantum Cosmology, University of Waterloo