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Quantum Spacetime Engineering

Bianca Dittrich Perimeter Institute for Theoretical Physics

April 22, 2014

PIRSA:14040089
Renormalization of group field theories: motivations and a brief review

Daniele Oriti Complutense University of Madrid

April 22, 2014

PIRSA:14040088
Causality constraints in gravitational theories
April 22, 2014

PIRSA:14040116
High Energy Physics
Tensor models in the large N limit

Razvan Gurau Universität Heidelberg

April 22, 2014

PIRSA:14040087
13/14 PSI - Explorations in Cosmology - Lecture 11

Matthew Johnson York University

April 22, 2014

PIRSA:14040056
What you always wanted to know about CDT, but did not have time to read about in our papers

Renate Loll Radboud Universiteit Nijmegen

April 22, 2014

PIRSA:14040086
Recent developments in asymptotic safety: tests and properties

Tim Morris University of Southampton

April 22, 2014

PIRSA:14040085
13/14 PSI - Explorations in Particle Theory - Lecture 11

Brian Shuve Harvey Mudd College

April 22, 2014

PIRSA:14040068
13/14 PSI - Explorations in Cosmology - Lecture 10

Matthew Johnson York University

April 21, 2014

PIRSA:14040055
13/14 PSI - Explorations in Particle Theory - Lecture 10

Brian Shuve Harvey Mudd College

April 21, 2014

PIRSA:14040016
Compact objects as dark-matter probes

Paolo Pani Instituto Superior Tecnico - Departamento de Física
April 17, 2014

PIRSA:14040078
General Relativity & Quantum Cosmology
Universal problems

David Mattingly University of New Hampshire
April 17, 2014

PIRSA:14040074
General Relativity & Quantum Cosmology

Quantum Spacetime Engineering

Bianca Dittrich Perimeter Institute for Theoretical Physics

April 22, 2014

PIRSA:14040089

Given (a set of) fundamental models of quantum space time, for instance spin foam models, we aim to understand the large scale physics encoded in these fundamental models. Renormalization and coarse graining address this issue and help to understand how large scale physics depends on parameters in the fundamental models.

I will review recent work on coarse graining and renormalization of spin foam and analogue models, revealing possible large scale phases, depending on parameters of the microscopic models. I will explain how these phases are connected to topological field theories and possible vacua for the theory of quantum gravity, e.g. loop quantum gravity. I outline how these different vacua are connected to different representations of the observable algebra, that is different Hilbert spaces, and how this allows to expand the theory around different vacuum states.
Renormalization of group field theories: motivations and a brief review

Daniele Oriti Complutense University of Madrid

April 22, 2014

PIRSA:14040088

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. Beside introducing the general formalism and clarifying the relation to other approaches, we will motivate the renormalisation group analysis of group field theories and review recent developments in this direction.
Causality constraints in gravitational theories
April 22, 2014

PIRSA:14040116
High Energy Physics
Tensor models in the large N limit

Razvan Gurau Universität Heidelberg

April 22, 2014

PIRSA:14040087

Tensor models generalize matrix models and provide a framework for the study of random geometries in arbitrary dimensions. Like matrix models they support a 1/N expansion, where N is the size of the tensor, with an analytically controlled large N limit. In this talk I will present some recent results in this field and I will discuss their implications for quantum gravity.
13/14 PSI - Explorations in Cosmology - Lecture 11

Matthew Johnson York University

April 22, 2014

PIRSA:14040056
What you always wanted to know about CDT, but did not have time to read about in our papers

Renate Loll Radboud Universiteit Nijmegen

April 22, 2014

PIRSA:14040086

I will review the approach of Causal Dynamical Triangulations to nonperturbative quantum gravity, high-lighting some frequently mis- or ununderstood features, emphasizing recent developments and discussing some interesting open issues.
Recent developments in asymptotic safety: tests and properties

Tim Morris University of Southampton

April 22, 2014

PIRSA:14040085

The talk will review recent tests of the asymptotic safety conjecture within functional renormalisation group studies and progress in understanding the properties that such a fixed point would have.
13/14 PSI - Explorations in Particle Theory - Lecture 11

Brian Shuve Harvey Mudd College

April 22, 2014

PIRSA:14040068
13/14 PSI - Explorations in Cosmology - Lecture 10

Matthew Johnson York University

April 21, 2014

PIRSA:14040055
13/14 PSI - Explorations in Particle Theory - Lecture 10

Brian Shuve Harvey Mudd College

April 21, 2014

PIRSA:14040016
Compact objects as dark-matter probes

Paolo Pani Instituto Superior Tecnico - Departamento de Física
April 17, 2014

PIRSA:14040078
General Relativity & Quantum Cosmology
In the last few years the possibility of constraining dark matter with astrophysical observations of compact objects, such as white dwarfs, neutron stars and black holes, has been explored. The ultra-high density interior of neutron stars and the strong-curvature regions near massive black holes make these objects unique laboratories to test weakly-interacting particles. In the first part of this talk I will review some recent work on the potential of compact objects as dark-matter detectors, including the consequences of dark-matter accretion on compact stars and superradiant black-hole instabilities triggered by ultralight bosons. In the second part I will discus how observations of neutron stars can be used to constrain the dark-matter fraction in primordial black holes. In a close encounter with a neutron star, a primordial black hole can get gravitationally captured due to accretion, dynamical friction and tidal heating. Within a short time, the black hole is trapped inside the star and disrupts it by rapid accretion. The mere existence of old neutron stars limits the abundance of primordial black holes in the only mass range that was still unconstrained, thus suggesting that these objects cannot be the dominant dark matter constituent.
Universal problems

David Mattingly University of New Hampshire
April 17, 2014

PIRSA:14040074
General Relativity & Quantum Cosmology
Arguments that gravity cannot be a local renormalizable quantum field theory come from both field theory lore and black hole physics. Two current approaches to quantum gravity, asymptotic safety and Horava-Lifshitz gravity, both of which treat quantum gravity as a local renormalizable QFT, are explicitly constructed to counter field theory arguments about the non-renormalizability of gravity. However, any proposed renormalizable theory of quantum gravity must also answer black hole physics based counter-arguments. Formulating these arguments concretely requires understanding black hole solutions and thermodynamics in these theories. For Horava-Lifshitz gravity this entails understanding the thermodynamics of universal horizons. I describe the current status of universal horizon physics and which aspects are/are not still in tension with the fundamental premise of renormalizability.

Title	Date	Collection	Type	Info
Quantum Spacetime Engineering	2014‑04‑22	Renormalization Group Approaches to Quantum Gravity	Conference	View details
Renormalization of group field theories: motivations and a brief review	2014‑04‑22	Renormalization Group Approaches to Quantum Gravity	Conference	View details
Causality constraints in gravitational theories	2014‑04‑22	Quantum Fields and Strings	Scientific Series	View details
Tensor models in the large N limit	2014‑04‑22	Renormalization Group Approaches to Quantum Gravity	Conference	View details
13/14 PSI - Explorations in Cosmology - Lecture 11	2014‑04‑22	13/14 PSI - Explorations in Cosmology	Course	View details
What you always wanted to know about CDT, but did not have time to read about in our papers	2014‑04‑22	Renormalization Group Approaches to Quantum Gravity	Conference	View details
Recent developments in asymptotic safety: tests and properties	2014‑04‑22	Renormalization Group Approaches to Quantum Gravity	Conference	View details
13/14 PSI - Explorations in Particle Theory - Lecture 11	2014‑04‑22	13/14 PSI - Explorations in Particle Theory	Course	View details
13/14 PSI - Explorations in Cosmology - Lecture 10	2014‑04‑21	13/14 PSI - Explorations in Cosmology	Course	View details
13/14 PSI - Explorations in Particle Theory - Lecture 10	2014‑04‑21	13/14 PSI - Explorations in Particle Theory	Course	View details
Compact objects as dark-matter probes	2014‑04‑17	Strong Gravity	Scientific Series	View details
Universal problems	2014‑04‑17	Quantum Gravity	Scientific Series	View details

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Format results

Quantum Spacetime Engineering

Renormalization of group field theories: motivations and a brief review

Causality constraints in gravitational theories

Tensor models in the large N limit

13/14 PSI - Explorations in Cosmology - Lecture 11

What you always wanted to know about CDT, but did not have time to read about in our papers

Recent developments in asymptotic safety: tests and properties

13/14 PSI - Explorations in Particle Theory - Lecture 11

13/14 PSI - Explorations in Cosmology - Lecture 10

13/14 PSI - Explorations in Particle Theory - Lecture 10

Compact objects as dark-matter probes

Universal problems

Quantum Spacetime Engineering

Renormalization of group field theories: motivations and a brief review

Causality constraints in gravitational theories

Tensor models in the large N limit

13/14 PSI - Explorations in Cosmology - Lecture 11

What you always wanted to know about CDT, but did not have time to read about in our papers

Recent developments in asymptotic safety: tests and properties

13/14 PSI - Explorations in Particle Theory - Lecture 11

13/14 PSI - Explorations in Cosmology - Lecture 10

13/14 PSI - Explorations in Particle Theory - Lecture 10

Compact objects as dark-matter probes

Universal problems