Talks by Daniele Oriti

Emergent cosmology from tensorial group field theories for quantum gravity

Daniele Oriti Ludwig-Maximilians-Universitiät München (LMU)

We introduce the basic elements of tensorial group field theories (TGFTs) for quantum gravity, emphasizing how they encode quantum geometry and their relation with canonical loop quantum gravity and spin foam models. Next, we discuss briefly the issue of continuum limit and how it could be understood in this framework.

The universe as a quantum gravity condensate.

Daniele Oriti Ludwig-Maximilians-Universitiät München (LMU)

I describe how, within the group field theory (GFT) formalism for quantum gravity, we can: 

 

1) provide a candidate description of the quantum building blocks of spacetime, bringing together ideas and mathematical structures from other quantum gravity formalisms;

 

2) apply powerful tools from quantum field theory, like the (perturbative and non-perturbative) renormalization group, to establish the quantum consistency of given GFT models and to study their continuum limit and phase structure;

 

Renormalization of group field theories: motivations and a brief review

Daniele Oriti Ludwig-Maximilians-Universitiät München (LMU)
Group field theories are tensorial models enriched with group-theoretic data in order to define proper field theories of quantum geometry. They can be understood as a second quantised (Fock space) reformulation of loop quantum gravity kinematics and dynamics. The renormalization group provides, as a in any quantum field theory, a key tool to select well-defined models, to unravel the impact of quantum effects on the dynamics across different scales, and to study the continuum limit.

Is spacetime fundamentally discrete?

Modelling continuum dynamics on discrete space time
We will discuss perfect discretizations which aim at mirroring exactly continuum physics on a given lattice. Such discretizations avoid typical artifacts like Lorentz violation, energy dissipation, particle doubling and in particular breaking of diffeomorphism symmetry. Thus the question arises how to distinguish such lattice dynamics from continuum physics.

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What is Space Made Of?

Daniele Oriti Ludwig-Maximilians-Universitiät München (LMU)
Quantum gravity is about finding out what is the more fundamental nature of spacetime, as a physical system. Several approaches to quantum gravity, suggest that the very description of spacetime as a continuum fails at shorter distances and higher energies, and should be replaced by one in terms of discrete, pre-geometric degrees of freedom, possibly of combinatorial and algebraic nature.

Introduction to quantum gravity - Part 21

Daniele Oriti Ludwig-Maximilians-Universitiät München (LMU)
This is an introduction to background independent quantum theories of gravity, with a focus on loop quantum gravity and related approaches. Basic texts: -Quantum Gravity, by Carlo Rovelli, Cambridge University Press 2005 -Quantum gravityy with a positive cosmological constant, Lee Smolin, hep-th/0209079 -Invitation to loop quantum gravity, Lee Smolin, hep-th/0408048 -Gauge fields, knots and gravity, JC Baez, JP Muniain Prerequisites: -undergraduate quantum mechanics -basics of classical gauge field theories -basic general relativity -hamiltonian and lagrangian mechanics -basics of lie a

Introduction to quantum gravity - Part 20

Daniele Oriti Ludwig-Maximilians-Universitiät München (LMU)
This is an introduction to background independent quantum theories of gravity, with a focus on loop quantum gravity and related approaches. Basic texts: -Quantum Gravity, by Carlo Rovelli, Cambridge University Press 2005 -Quantum gravityy with a positive cosmological constant, Lee Smolin, hep-th/0209079 -Invitation to loop quantum gravity, Lee Smolin, hep-th/0408048 -Gauge fields, knots and gravity, JC Baez, JP Muniain Prerequisites: -undergraduate quantum mechanics -basics of classical gauge field theories -basic general relativity -hamiltonian and lagrangian mechanics -basics of lie a

Introduction to quantum gravity - Part 19

Daniele Oriti Ludwig-Maximilians-Universitiät München (LMU)
This is an introduction to background independent quantum theories of gravity, with a focus on loop quantum gravity and related approaches. Basic texts: -Quantum Gravity, by Carlo Rovelli, Cambridge University Press 2005 -Quantum gravityy with a positive cosmological constant, Lee Smolin, hep-th/0209079 -Invitation to loop quantum gravity, Lee Smolin, hep-th/0408048 -Gauge fields, knots and gravity, JC Baez, JP Muniain Prerequisites: -undergraduate quantum mechanics -basics of classical gauge field theories -basic general relativity -hamiltonian and lagrangian mechanics -basics of lie a