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marcus
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I've gathered the titles and abstracts of ESQG talks for which the slides have already been posted. Hopefully more links will show up tomorrow, as the workshop proceeds.
Links to the slides PDF are included alongside the speaker's name in the schedule, here:
http://www.sissa.it/app/esqg2014/schedule.php
Jose Manuel Carmona (Universidad de Zaragoza) (slides)
16:30, Mon 1st Sep 2014
Thresholds in the presence of Lorentz violating kinematics including modified conservation laws
We discuss the leading Lorentz violations in the kinematics of particle processes with modified dispersion relations and modified composition law of momenta and some phenomenological implications on thresholds in different reactions.
Paolo Creminelli (ICTP, Trieste) (slides)
11:15, Tue 2nd Sep 2014
B-mode cosmology
The experimental sensitivity to B-modes is now in an interesting regime for primordial tensor modes. I will review the robustness of the tensor mode prediction in inflation and speculate about what we can learn if tensor modes are detected.
Astrid Eichhorn (Perimeter Institute, Waterloo) (slides)
10:45, Mon 1st Sep 2014
Testing asymptotically safe quantum gravity through coupling to dynamical matter
I will discuss the main idea of asymptotically safe quantum gravity. I will then focus on the effect of dynamical matter degrees of freedom, and discuss the evidence for the consistency of the asymptotic safety scenario for gravity with the Standard Model. Further, I will explain why only some models of "New Physics" seem to be compatible with asymptotic safety, thus providing a possibility to experimentally rule out asymptotic safety at the LHC or future colliders.
Giampiero Esposito (INFN, Sezione di Napoli) (slides)
17:00, Mon 1st Sep 2014
Three-body problem in effective field theories of gravity
The quantum corrections to the Newtonian potential obtained in effective field theories of gravity are shown to produce tiny but nonnegligible effects. For example, in the restricted problem of 3 bodies, the coordinates of Lagrangian points are slightly modified, and the planetoid is no longer at equal distance from the two bodies of large mass in the configuration of stable equilibrium. The equations of the full 3-body problem are also under investigation in the presence of quantum corrections.
Agnes Ferte (Institut d'Astrophysique Spatiale) (slides)
17:00, Tue 2nd Sep 2014
Constraints on chiral gravity through the CMB polarization
If parity invariance is broken in the primordial universe, the cosmic microwave background TB and EB cross-correlations, usually vanishing, become non zero. Their detection would then constrain the level of parity violation. I propose to present forecasts on the detection of this parameter by realistically estimating the uncertainties on the TB and EB spectra via the pure pseudo spectrum method, which efficiency has been shown. I will present the results of this forecast in the case of two typical experimental setups: a small-scale experiment and a large scale survey. Our results show that no constraints can be put on the level of parity violation in the former case. However a range of model would be accessible with a future CMB satellite-like mission: for instance, a parity violation of at least 50% with r = 0.2 could be detected.
Julien Grain (Institut d'Astrophysique Spatiale) (slides)
16:30, Tue 2nd Sep 2014
A brief overview of loop quantum cosmology and its potential observational signatures
Loop quantum cosmology (a symmetry-reduced quantum model of the Universe inspired by loop quantum gravity) extends the inflationary paradigm to the Planck era: the big bang singularity is replaced by a quantum bounce naturally followed by inflation. Testing for these models requires to compute the amount of cosmological perturbations produced in this quantum background and subsequently derives their footprints on the cosmic microwave background. I propose to review two theoretical approaches treating for cosmological perturbations in a quantum background (see Barrau et al. 2014 and Agullo et al. 2013), making their respective assumptions and methodology as explicit as possible. I will then show the observational consequences of those treatments focusing on the specific case of the cosmic microwave background anisotropies as a probe of the primordial Universe.
Brian Keating (University of California, San Diego ) (slides)
9:00, Tue 2nd Sep 2014
The discovery of primordial B-mode polarization
The era of Cosmic Microwave Background B-mode polarization cosmology has recently begun. The BICEP2 telescope observed from the South Pole for three seasons (2010�2012) and released results showing an excess of B-modes in the range 30 < ell < 150 with >5 sigma significance. We find that this excess can not be explained by instrumental systematics or foregrounds. The signal was confirmed in cross-correlation with BICEP1 (at 100 and 150 GHz) and preliminary data from the Keck Array. The observed B-mode power spectrum is well-fit by a lensed-LCDM cosmological model with the addition of primordial tensor fluctuations with tensor-to-scalar ratio r=0.20^{+0.07}_{-0.05}. I will discuss the BICEP2 experiment, observations, and data analysis, as well as current and planned efforts to follow up this detection.
Francesco Marin (Universita' di Firenze and INFN) (slides)
14:30, Mon 1st Sep 2014
Tests of quantum gravity with macroscopic mechanical oscillators
General relativity and quantum physics are expected to merge at the Planck scale, defined by distances of the order of 1.6x10^-35 m and/or extremely high energies of the order of 1.2x10^19 GeV. Since the study of particles collisions around the Planck energy is well beyond the possibilities of current and foreseeable accelerators, high-energy astronomical events (e.g. gamma-ray bursts) have been considered as the privileged natural system to unveil quantum gravitational effects. This common view has been enriched in the last years thanks to a number of studies proposing that signatures of the Planck-scale physics could manifest also at low energies. It is indeed widely accepted that, when gravity is taken into account, deviations from standard quantum mechanics are expected. In particular, we have recently shown that the very low mechanical energy achieved and measured in a vibration mode of a massive object can set an upper limit to possible modifications of the Heisenberg uncertainty principle, that are expected as an effect of gravity. We have indeed exploited the sub- millikelvin cooling of the normal modes of the ton-scale gravitational wave detector AURIGA at this purpose [1]. Here we will discuss some possible interpretations of our results, including possible consequences on deformed commutators, and an upper limit on the length scale at which quantum fluctuations of the space- time geometry should come into play[2]. We will also describe the preliminary results of a series of experiments devoted to investigate possible modifications to the dynamics of micro-oscillators, due to modified Heisenberg relations. [1] F. Marin et al., "Gravitational bar detectors set limits to Planck-scale physics on macroscopic variables", Nature Phys. 9, 71 (2013) [2] F. Marin et al., "Investigation of Planck scale physics by the AURIGA gravitational bar detector", to be published on New J. Phys.
Mercedes Martin-Benito (Radboud University Nijmegen) (slides)
17:30, Tue 2nd Sep 2014
Echoes of the early Universe
By applying quantum informational and optical tools to quantum gravity theories in the very early universe, we show that the fluctuations of quantum fields as seen by late comoving observers are significantly influenced by the history of the early universe, transmitting information about the nature of the universe in timescales when quantum gravitational effects where non-negligible. This might be observable even nowadays thus used to build falsifiability tests of quantum gravity theories.
Links to the slides PDF are included alongside the speaker's name in the schedule, here:
http://www.sissa.it/app/esqg2014/schedule.php
Jose Manuel Carmona (Universidad de Zaragoza) (slides)
16:30, Mon 1st Sep 2014
Thresholds in the presence of Lorentz violating kinematics including modified conservation laws
We discuss the leading Lorentz violations in the kinematics of particle processes with modified dispersion relations and modified composition law of momenta and some phenomenological implications on thresholds in different reactions.
Paolo Creminelli (ICTP, Trieste) (slides)
11:15, Tue 2nd Sep 2014
B-mode cosmology
The experimental sensitivity to B-modes is now in an interesting regime for primordial tensor modes. I will review the robustness of the tensor mode prediction in inflation and speculate about what we can learn if tensor modes are detected.
Astrid Eichhorn (Perimeter Institute, Waterloo) (slides)
10:45, Mon 1st Sep 2014
Testing asymptotically safe quantum gravity through coupling to dynamical matter
I will discuss the main idea of asymptotically safe quantum gravity. I will then focus on the effect of dynamical matter degrees of freedom, and discuss the evidence for the consistency of the asymptotic safety scenario for gravity with the Standard Model. Further, I will explain why only some models of "New Physics" seem to be compatible with asymptotic safety, thus providing a possibility to experimentally rule out asymptotic safety at the LHC or future colliders.
Giampiero Esposito (INFN, Sezione di Napoli) (slides)
17:00, Mon 1st Sep 2014
Three-body problem in effective field theories of gravity
The quantum corrections to the Newtonian potential obtained in effective field theories of gravity are shown to produce tiny but nonnegligible effects. For example, in the restricted problem of 3 bodies, the coordinates of Lagrangian points are slightly modified, and the planetoid is no longer at equal distance from the two bodies of large mass in the configuration of stable equilibrium. The equations of the full 3-body problem are also under investigation in the presence of quantum corrections.
Agnes Ferte (Institut d'Astrophysique Spatiale) (slides)
17:00, Tue 2nd Sep 2014
Constraints on chiral gravity through the CMB polarization
If parity invariance is broken in the primordial universe, the cosmic microwave background TB and EB cross-correlations, usually vanishing, become non zero. Their detection would then constrain the level of parity violation. I propose to present forecasts on the detection of this parameter by realistically estimating the uncertainties on the TB and EB spectra via the pure pseudo spectrum method, which efficiency has been shown. I will present the results of this forecast in the case of two typical experimental setups: a small-scale experiment and a large scale survey. Our results show that no constraints can be put on the level of parity violation in the former case. However a range of model would be accessible with a future CMB satellite-like mission: for instance, a parity violation of at least 50% with r = 0.2 could be detected.
Julien Grain (Institut d'Astrophysique Spatiale) (slides)
16:30, Tue 2nd Sep 2014
A brief overview of loop quantum cosmology and its potential observational signatures
Loop quantum cosmology (a symmetry-reduced quantum model of the Universe inspired by loop quantum gravity) extends the inflationary paradigm to the Planck era: the big bang singularity is replaced by a quantum bounce naturally followed by inflation. Testing for these models requires to compute the amount of cosmological perturbations produced in this quantum background and subsequently derives their footprints on the cosmic microwave background. I propose to review two theoretical approaches treating for cosmological perturbations in a quantum background (see Barrau et al. 2014 and Agullo et al. 2013), making their respective assumptions and methodology as explicit as possible. I will then show the observational consequences of those treatments focusing on the specific case of the cosmic microwave background anisotropies as a probe of the primordial Universe.
Brian Keating (University of California, San Diego ) (slides)
9:00, Tue 2nd Sep 2014
The discovery of primordial B-mode polarization
The era of Cosmic Microwave Background B-mode polarization cosmology has recently begun. The BICEP2 telescope observed from the South Pole for three seasons (2010�2012) and released results showing an excess of B-modes in the range 30 < ell < 150 with >5 sigma significance. We find that this excess can not be explained by instrumental systematics or foregrounds. The signal was confirmed in cross-correlation with BICEP1 (at 100 and 150 GHz) and preliminary data from the Keck Array. The observed B-mode power spectrum is well-fit by a lensed-LCDM cosmological model with the addition of primordial tensor fluctuations with tensor-to-scalar ratio r=0.20^{+0.07}_{-0.05}. I will discuss the BICEP2 experiment, observations, and data analysis, as well as current and planned efforts to follow up this detection.
Francesco Marin (Universita' di Firenze and INFN) (slides)
14:30, Mon 1st Sep 2014
Tests of quantum gravity with macroscopic mechanical oscillators
General relativity and quantum physics are expected to merge at the Planck scale, defined by distances of the order of 1.6x10^-35 m and/or extremely high energies of the order of 1.2x10^19 GeV. Since the study of particles collisions around the Planck energy is well beyond the possibilities of current and foreseeable accelerators, high-energy astronomical events (e.g. gamma-ray bursts) have been considered as the privileged natural system to unveil quantum gravitational effects. This common view has been enriched in the last years thanks to a number of studies proposing that signatures of the Planck-scale physics could manifest also at low energies. It is indeed widely accepted that, when gravity is taken into account, deviations from standard quantum mechanics are expected. In particular, we have recently shown that the very low mechanical energy achieved and measured in a vibration mode of a massive object can set an upper limit to possible modifications of the Heisenberg uncertainty principle, that are expected as an effect of gravity. We have indeed exploited the sub- millikelvin cooling of the normal modes of the ton-scale gravitational wave detector AURIGA at this purpose [1]. Here we will discuss some possible interpretations of our results, including possible consequences on deformed commutators, and an upper limit on the length scale at which quantum fluctuations of the space- time geometry should come into play[2]. We will also describe the preliminary results of a series of experiments devoted to investigate possible modifications to the dynamics of micro-oscillators, due to modified Heisenberg relations. [1] F. Marin et al., "Gravitational bar detectors set limits to Planck-scale physics on macroscopic variables", Nature Phys. 9, 71 (2013) [2] F. Marin et al., "Investigation of Planck scale physics by the AURIGA gravitational bar detector", to be published on New J. Phys.
Mercedes Martin-Benito (Radboud University Nijmegen) (slides)
17:30, Tue 2nd Sep 2014
Echoes of the early Universe
By applying quantum informational and optical tools to quantum gravity theories in the very early universe, we show that the fluctuations of quantum fields as seen by late comoving observers are significantly influenced by the history of the early universe, transmitting information about the nature of the universe in timescales when quantum gravitational effects where non-negligible. This might be observable even nowadays thus used to build falsifiability tests of quantum gravity theories.