Name: XXV SIGRAV Conference on General Relativity and Gravitation
Start: 2023-09-04T08:00:00+02:00
End: 2023-09-08T18:00:00+02:00
Location: SISSA (Miramare campus)

XXV SIGRAV Conference on General Relativity and Gravitation

from Monday, September 4, 2023 (8:00 AM) to Friday, September 8, 2023 (6:00 PM)

Monday, September 4, 2023

8:00 AM Registration and Welcome
Registration and Welcome
8:00 AM - 8:45 AM
Room: Aula Magna

8:45 AM Welcome SISSA Director, INFN TS Director & SIGRAV President
Welcome SISSA Director, INFN TS Director & SIGRAV President
8:45 AM - 9:00 AM
Room: Aula Magna, Room A, B, D
9:00 AM Jcap Colloquium-Parity Violation in Cosmology - Eiichiro Komatsu
Jcap Colloquium-Parity Violation in Cosmology
- Eiichiro Komatsu
9:00 AM - 10:00 AM
Room: Aula Magna Parity symmetry is known to be violated in the weak interaction. Do the physical laws behind the unsolved problems of modern cosmology - cosmic inflation, dark matter, and dark energy - also violate parity symmetry? In this talk, we will discuss theoretical and observational possibilities of parity violation in cosmology, a topic that has received much attention in recent years.
10:00 AM Coffe break
Coffe break
10:00 AM - 10:30 AM
10:30 AM Binary Neutron Stars: from macroscopic collisions to microphysics - Luciano Rezzolla
Binary Neutron Stars: from macroscopic collisions to microphysics
- Luciano Rezzolla
10:30 AM - 11:30 AM
Room: Aula Magna I will argue that if black holes represent one the most fascinating implications of Einstein's theory of gravity, neutron stars in binary system are its richest laboratory, where gravity blends with astrophysics and particle physics. I will discuss the rapid recent progress made in modelling these systems and show how the gravitational signal can provide tight constraints on the equation of state and sound speed for matter at nuclear densities, as well as on one of the most important consequences of general relativity for compact stars: the existence of a maximum mass. Finally, I will discuss how the merger may lead to a phase transition from hadronic to quark matter. Such a process would lead to a signature in the post-merger gravitational-wave signal and open an observational window on the production of quark matter in the present Universe.
11:30 AM Amplitudes in AdS from conformal field theory - Agnese Bissi
Amplitudes in AdS from conformal field theory
- Agnese Bissi
11:30 AM - 12:30 PM
Room: Aula Magna In this talk I discuss a method to study amplitudes in AdS in the context of the AdS/CFT correspondence. In particular I will discuss how to study loop amplitudes by using the holographic CFT counterpart.
12:30 PM Lunch
Lunch
12:30 PM - 2:00 PM
2:00 PM Experiments
Experiments
2:00 PM - 5:45 PM
Room: Room B
Contributions

2:00 PM Experiments: Status of the GINGER project - Angela Di Virgilio

2:30 PM Experiments: Fundamental Physics with GNSS satellites and the Galileo for Science Project - Feliciana Sapio (IAPS-INAF)

3:00 PM Experiments: METRIC: a mission concept for upper atmosphere mapping, gravitational physics and geodesy - Roberto Peron (INAF-IAPS)

4:00 PM Experiments: Galactic Dark Matter from General Relativity - Federico Re (Milano Bicocca)

4:30 PM Experiments: ISA accelerometer on-board BepiColombo mission during first Mercury swing-bys – Preliminary observations - Francesco Santoli (IAPS-INAF)

5:00 PM ###
Phenomenology
Phenomenology
2:00 PM - 5:45 PM
Room: Room A
Contributions

2:00 PM Phenomenology: Detection and measurement prospects at the Einstein Telescope: forecasts with GWFAST - Francesco Iacovelli (University of Geneva)

2:30 PM Phenomenology: Parameter estimation of binary black holes in the endpoint of the up--down instability - Viola De Renzis (University of Milano-Bicocca)

3:00 PM Phenomenology: Multitimescale dynamics of eccentric and precessing binary black holes - Giulia Fumagalli (University of Milano-Bicocca)

3:15 PM Phenomenology: Anisotropic Neutron Stars: Exploring Quasinormal Modes in Full General Relativity - Sushovan Mondal (The Institute of Mathematical Sciences, Chennai, India)

4:00 PM Phenomenology: Glitch systematics on the observation of massive black-hole binaries with LISA - Alice Spadaro (University of MIlano-Bicocca)

4:15 PM Phenomenology: Non-gaussian gravitational wave backgrounds across the GW spectrum - Riccardo Buscicchio (Università di Milano-Bicocca)

4:30 PM Phenomenology: From regular black holes to horizonless objects: gravitational perturbations and detectability - Vania Vellucci (Sissa)

4:45 PM Phenomenology: AGILE search of gamma-ray electromagnetic counterparts of gravitational waves - Francesco Longo

5:00 PM ###
Theory
Theory
2:00 PM - 5:45 PM
Room: Room D
Contributions

2:00 PM Theory: Exploring Conserved Charges in General Relativity Using Covariant Phase Space - Gloria Odak (CPT Marseille)

2:15 PM Theory: The quantum states of the universe in tomographic form - Cosimo Stornaiolo (INFN-Sezione di Napoli)

2:30 PM Theory: On the classification of Generalized Quasitopological Gravities - Ángel Jesús Murcia Gil (Istituto Nazionale di Fisica Nucleare, Sezione di Padova (Italia))

2:45 PM Theory: On the canonical equivalence of Jordan and Einstein frames - Gabriele Gionti, S.J. (Specola Vaticana (Vatican Observatory) and LNF-INFN Frascati)

3:00 PM Theory: On the nature of Bondi-Metzner-Sachs transformations - Giampiero Esposito (University Federico II Naples and INFN Naples Section)

3:15 PM Theory: Can General Relativity Play a Role in Galactic dynamics? - Matteo Luca Ruggiero (Università degli Studi di Torino and INFN - LNL)

4:00 PM Theory: Probing the Big Bang with Quantum Fields - Marc Schneider (SISSA)

4:15 PM Theory: Primordial fluctuations from quantum gravity - Francesca Vidotto (Western University, Canada)

4:30 PM Theory: Scale-invariant inflation - Chiara Cecchini (University of Trento, TIFPA-INFN)

4:45 PM Theory: Bianchi-I cosmologies, magnetic fields and singularities - Alexander Kamenshchik (INFN)

5:00 PM Theory: A Cosmographic distance functional between Celestial Spheres - Francesca Familiari (Università di Pavia, INFN)

5:15 PM Theory: Grand canonical ensemble of a d-dimensional Reissner-Nordström black hole space in a cavity - Tiago Fernandes (GRIT - CENTRA, IST)
Tuesday, September 5, 2023
9:00 AM Gluing, black holes, and all that - Piotr Chruściel
Gluing, black holes, and all that
- Piotr Chruściel
9:00 AM - 10:00 AM
Room: Aula Magna I will review recent progress on gluing methods for constructing solutions of the Einstein equations, and other progress in mathematical general relativity
10:00 AM Coffe Break
Coffe Break
10:00 AM - 10:30 AM
10:30 AM Advance Virgo+ Quantum Noise Reduction system for O4 - Martina De Laurentis
Advance Virgo+ Quantum Noise Reduction system for O4
- Martina De Laurentis
10:30 AM - 11:30 AM
Room: Aula Magna One of the fundamental noise in gravitational waves detectors is the so called Quantum Noise, that is related to the intrinsic quantum nature of the laser used to interrogate the GW interferometers, i.e. to the uncertainty on amplitude and phase of the coherent state of light that couples with the vacuum fluctuations. Due to the frequency dependent opto-mechanical response of the GW detectors, the amplitude and phase fluctuations is weighted in different way in the detectors frequency band, leading to the so called Radiation Pression Noise (RPN) at low frequency and to the so called Shot Noise (SN) at high frequency, respectively. By injecting frequency independent squeezed (FIS) vacuum light into the dark port of the GW interferometer a significant reduction of the SN can be and has been observed during the last observations runs, both for Advance Virgo and the two LIGO detectors. Nevertheless the big effort done to reduce in parallel one of the most sensitivity limiting noise in the low frequency region, the technical noise, has revealed the main draw back of the FIS injection: the increasing of the RPN at low frequency. Moreover, even without FIS injection, the improvement of the low frequency sensitivity for the new upgraded detectors, in any case leads to the needed of the quantum noise mitigation in the whole detectors band. For this reason FIS injection has been replaced with frequency dependent squeezed vacuum (FDS). For the current observation run, both Virgo and LIGO collaboration prepared FDS injection. The technique to produce it is based on the phase sensitive response of a filter cavity that allows the squeezing ellipse rotation in the detectors frequency band. Here, after a general introduction to the QN and the FDS technique, we will present the status of the Quantum Noise Reduction system for the FDS injection into AdV+.
11:30 AM Black hole spectroscopy - Vitor Cardoso
Black hole spectroscopy
- Vitor Cardoso
11:30 AM - 12:30 PM
Room: Aula Magna One of the most remarkable possibilities of General Relativity concerns gravitational collapse to black holes. Is the strong field dynamical regime of gravity well described by General Relativity? I will summarize the status of black hole spectroscopy and attemps at probing near horizon physics.
12:30 PM Lunch+CD SIGRAV Meeting
Lunch+CD SIGRAV Meeting
12:30 PM - 2:00 PM
2:00 PM Experiments
Experiments
2:00 PM - 6:00 PM
Room: Aula Magna, Room A, B, D
Contributions

2:00 PM Experiments: Detecting low-frequency gravitational waves with Pulsar Timing Arrays - Delphine Perrodin (INAF - Osservatorio Astronomico di Cagliari)

2:30 PM Experiments: The European Pulsar Timing Array - the pulsar dataset - Golam Shaifullah (Dipartimento di Fisica ``G. Occhialini", Universit{\'a} degli Studi di Milano-Bicocca, Piazza della Scienza 3, I-20126 Milano, Italy)

3:00 PM Experiments: The second data release from the European Pulsar Timing Array II. Customised Pulsar Noise Models for Spatially Correlated Gravitational Waves - Aurélien Chalumea

4:00 PM Experiments: Impications of GW searches in the latest data release of the EPTA - Alberto Sesana (Universita` di Milano Bicocca)

4:30 PM Experiments: The growing population of the relativistic pulsar binaries - Andrea Possenti (INAF-Osservatorio Astronomico di Cagliari)

5:00 PM ###
Phenomenology
Phenomenology
2:00 PM - 6:00 PM
Room: Aula Magna, Room A, B, D
Contributions

2:00 PM Phenomenology: Scalar-tensor theories to tackle cosmological tensions - Mario Ballardini (University of Ferrara)

2:30 PM Phenomenology: Observational phenomena on black hole with dark matter dress - Xing-Yu Yang (Korea Institute for Advanced Study)

2:45 PM Phenomenology: Non-ideal GRMHD and compact objects - Luca Del Zanna (Università di Firenze)

3:00 PM Phenomenology: Dark Matter in Fractional Gravity I: Astrophysical Tests on Galactic Scales - francesco benetti (SISSA)

3:15 PM Phenomenology: Ultraviolet Sensitivity of Peccei–Quinn Inflation - Davide Dal Cin (Sissa)

4:00 PM Phenomenology: Testing Planck-scale in-vacuo dispersion with GRB neutrinos - Giacomo Rosati (Institute of Theoretical Physics, Wrocław University)

4:15 PM Phenomenology: Anharmonic effects on the squeezing of axions perturbations - Valentina Danieli (SISSA)

4:30 PM Phenomenology: A new Paradigm for the Dark Matter Phenomenon - Paolo Salucci (SISSA)

4:45 PM Phenomenology: Enlightening Cold Dark Matter's darkest side via a non-minimal coupling - Giovanni Gandolfi (SISSA)

5:00 PM Phenomenology: Spectrogram correlated stacking: A time-frequency domain analysis of the Stochastic Gravitational Wave Background - Ramit Dey (Western University, perimeter institute)

5:15 PM Phenomenology: Primordial Black Holes during the QCD phase-transition - Ilia Musco (INFN, La SAPIENZA University of Rome)

5:30 PM ###
Theory
Theory
2:00 PM - 6:00 PM
Room: Aula Magna, Room A, B, D
Contributions

2:00 PM Theory: Beyond the Casimir Wormholes - Remo Garattini (Università degli Studi di Bergamo)

2:15 PM Theory: Lessons from gravitational physics and beyond: how can we rethink space, time and causal order? - Silvia De Bianchi (University of Milan)

2:30 PM Theory: Fundamental decoherence from quantum spacetime - Vittorio D'Esposito (University of Naples Federico II)

2:45 PM Theory: Carrollian and Galilean limits of deformed symmetries in 3D gravity - Tomasz Trzesniewski (University of Wroclaw)

3:00 PM Theory: Quantum Euler angles and agency-dependent spacetime - Giuseppe Fabiano (University of Naples "Federico II")

3:15 PM Theory: A quantum-spacetime model with kinematical IR/UV mixing and its phenomenology - Domenico Frattulillo (University of Naples "Federico II")

4:00 PM Theory: Axially symmetric stationary gravitational perturbations of Kerr black hole --- Debye vs Weyl\,--\,Lewis\,--\,Papapetrou - David Kofron (Institute of Theoretical Physics, Faculty of Mathematics and Physics, Charles University)

4:15 PM Theory: To Kerr or not to Kerr? - Polina Petriakova (INFN)

4:30 PM Theory: On the dynamics of perturbed Black Holes - Michele Lenzi (Institute of Space Sciences (ICE-CSIC, IEEC), Barcelona)

4:45 PM Theory: Regular Black Holes in Lorentz-violating Gravity - Jacopo Mazza (SISSA, Trieste)

5:00 PM Theory: Black-hole evolution in the presence of scalar fields - Marco De Cesare

5:15 PM Theory: Unveiling Novel Scalarized Black Hole Solutions in Modified Theories - Zakaria Belkhadria (Université de Genève / Universita di Cagliari/ INFN theory)

5:30 PM Theory: Quantum field corrections to the equation of state of freely streaming matter in the FLRW space-time - Francesco Becattini
Wednesday, September 6, 2023

8:45 AM Assemblea dei Soci (in Italian, reserved to SIGRAV members)
Assemblea dei Soci (in Italian, reserved to SIGRAV members)
8:45 AM - 9:30 AM
Room: Aula Magna

9:30 AM Awards Ceremony (Premio Rampa, SIGRAV Prizes, Amaldi Medals) + Group Photo
Awards Ceremony (Premio Rampa, SIGRAV Prizes, Amaldi Medals) + Group Photo
9:30 AM - 10:00 AM
Room: Aula Magna

10:00 AM Coffe Break
Coffe Break
10:00 AM - 10:30 AM
10:30 AM Telescopes on the Moon: the next decades - Joseph Silk
Telescopes on the Moon: the next decades
- Joseph Silk
10:30 AM - 11:30 AM
Room: Aula Magna I will review the prospects for future progress in cosmology. The lunar surface allows a unique way forward, to go well beyond current limits. The far side provides a unique radio-quiet environment for probing the dark ages via 21 cm interferometry to seek elusive clues on the nature of inflation via the infinitesimal fluctuations that seeded galaxy formation. Far-infrared telescopes in cold and dark lunar polar craters will probe the cosmic microwave background radiation back to the first months of the Big Bang.
11:30 AM Gravitational scattering and radiation: from gedanken to real experiments - Gabriele Veneziano
Gravitational scattering and radiation: from gedanken to real experiments
- Gabriele Veneziano
11:30 AM - 12:30 PM
Room: Aula Magna I will attempt to summarize some 35 years of work on semiclassical gravitational scattering, from the early days of (gedanken) transplanckian-energy collisions of particles and strings, to the recent era of (real) black hole encounters. I will emphasize some interesting lessons that the former problem can provide for the latter, while stressing the danger of claiming too naive a connection between the two regimes.
12:30 PM Lunch
Lunch
12:30 PM - 2:00 PM
2:00 PM Searching for dark energy off the beaten track - Sunny Vagnozzi
Searching for dark energy off the beaten track
- Sunny Vagnozzi
2:00 PM - 2:30 PM
Room: Aula Magna Most of our attempts towards understanding dark energy (DE) have focused on using standard cosmological observations to probe its gravitational signatures, and in particular its equation of state. However, there is potentially a lot to be learned about DE by getting off the beaten track. This talk will discuss the results of my work in this direction over the past 5 years, which include developing new terrestrial searches for non-gravitational signatures of DE and new ultra-light particles, as well as cosmological and astrophysical tests of DE based on new non-standard probes.
2:30 PM Phenomenology of quantum gravity - Giulia Gubitosi
Phenomenology of quantum gravity
- Giulia Gubitosi
2:30 PM - 3:00 PM
Room: Aula Magna In this talk, I will present an overview of the latest progress in the field of quantum gravity phenomenology, focussing on some of the most relevant features of models where the Planck scale governs deformations of relativistic symmetries and illustrating opportunities for experimental tests. These include astrophysical observations, sensitive to residual signatures at low energies, cosmological observations about primordial perturbations, which are directly influenced by Planck-scale physics, and tests using quantum systems which might be sensitive to Planck-scale decoherence.
3:00 PM Probing new physics on the horizon of black holes with gravitational waves - Elisa Maggio
Probing new physics on the horizon of black holes with gravitational waves
- Elisa Maggio
3:00 PM - 3:30 PM
Room: Aula Magna Black holes are the most compact objects in the Universe. According to general relativity, black holes have a horizon that hides a singularity where Einstein’s theory breaks down. Recently, gravitational waves opened the possibility to probe the existence of horizons and investigate the nature of compact objects. This is of particular interest given some quantum-gravity models which predict the presence of horizonless and singularity-free compact objects. Such exotic compact objects can emit a different gravitational-wave signal relative to the black hole case. In this talk, I will give an overview of tests of the nature of compact objects with present and future gravitational-wave observations, including ringdown tests and searches for near-horizon structures with gravitational-wave echoes.
3:30 PM Social Trip to Aquileia (from Via Beirut-Return to Piazza Oberdan)
Social Trip to Aquileia (from Via Beirut-Return to Piazza Oberdan)
3:30 PM - 8:00 PM
Thursday, September 7, 2023
9:00 AM Gravitation and Cosmology - Nicola Vittorio
Gravitation and Cosmology
- Nicola Vittorio
9:00 AM - 10:00 AM
Room: Aula Magna I will review the main steps, both theoretical and experimental, which led the so-called LambdaCDM model to be both useful and successful. I will briefly mention the tensions among different cosmological observations. Finally I will discuss the perspectives of space-born missions and ground-based experiments to test the inflationary scenario via the possible detection of the B-modes of the Cosmic Microwave polarized Background.
10:00 AM Coffe Break
Coffe Break
10:00 AM - 10:30 AM
10:30 AM Shift symmetry in the dark sector - Prado Martín-Moruno
Shift symmetry in the dark sector
- Prado Martín-Moruno
10:30 AM - 11:30 AM
Room: Aula Magna The standard model of cosmology is a very successful effective tool to describe our Universe. However, there are theoretical and observational motivations to explore different fundamental paradigms for the dark sector. Assuming shift symmetry and minimally coupling to gravity as guiding principles, I will argue that one should go beyond the simplest scalar field case to find interesting phenomenology. Following this spirit, I will present some results obtained in two different scenarios: dark energy modelled with Kinetic Gravity Braiding and a dark sector invariant under transverse diffeomorphisms.
11:30 AM Einstein Telescope and the next generation GW observatories: science, technologies and perspectives - Michele Punturo
Einstein Telescope and the next generation GW observatories: science, technologies and perspectives
- Michele Punturo
11:30 AM - 12:30 PM
Room: Aula Magna A new generation of gravitational wave (GW) observatories will pick up in the next decade; it will be the legacy of the current generation of GW detectors, Advanced LIGO and Advanced Virgo, allowing the exploration of almost the entire Universe through GW signals. Einstein Telescope (ET) in Europe and Cosmic Explorer (CE) in US are the pioneer projects aiming to the realisation of a 3rd generation Gravitational Wave Observatory. Benefiting of the momentum given by the scientific successes of the LIGO and Virgo detectors, ET had, in the last few years, important boosts toward its realisation entering in several national and international roadmaps and receiving the support of many European agencies. ET and CE, working together and/or standalone, will be simultaneously new discovery and precision measurement observatories; they have a rich variety of scientific and multidisciplinary targets in astrophysics, nuclear physics, fundamental physics and cosmology. In fact, for example, ET aims to investigate almost the whole Universe, up to the dark ages, through the coalescence of stellar and intermediate mass black holes; it will detect and measure in great detail the gravitational wave signal generated by hundreds of thousands coalescences of neutron stars per year, revealing the nuclear physics governing this kind of stars. ET will be also a technological challenge: in order to achieve the expected sensitivity a new underground research infrastructure will be realised, a multi-interferometer per detector design will be implemented hosting new or updated technologies studied to reduce the noises limiting the current detectors. An overview of the ET observatory science targets, of the observatory design, of the needed technologies and project organisation, will be presented.
12:30 PM Lunch
Lunch
12:30 PM - 2:00 PM
2:00 PM Experiments
Experiments
2:00 PM - 5:45 PM
Room: Aula Magna, Room A, B, D
Contributions

2:00 PM Experiments: The Astrometric Gravitational Arena: principles and applications - Mariateresa Crosta

2:30 PM Experiments: Progress on the Astrometric Gravitational Wave Antennas - Mario G. Lattanzi

3:00 PM Experiments: LISA Pathfinder and LISA test-mass charging - Catia Grimani

4:00 PM Experiments: Large area space interferometry to measure Solar and galactic gravitomagnetism - Massimo Bassan

4:30 PM LAG- Liquid Actuated Gravity - Snooping Inverse Square Law at cm distance - Massimo Bassan (University of Roma Tor Vergata, Roma, Italy)

5:00 PM ###
Phenomenology
Phenomenology
2:00 PM - 5:45 PM
Room: Aula Magna, Room A, B, D
Contributions

2:00 PM Phenomenology: Neural Posterior Estimation with guaranteed exact coverage: the ringdown of GW150914 - Marco Crisostomi (SISSA)

2:30 PM Phenomenology: Testing black hole eikonal correspondence - Che-Yu Chen (iTHEMS, RIKEN)

2:45 PM Phenomenology: Hunting for two rings in black hole images - Raúl Carballo-Rubio (CP3-Origins, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark)

3:00 PM Phenomenology: Testing GR with large catalogs: the cosmic variance of hierarchical stacking - Costantino Pacilio (Università degli Studi di Milano Bicocca)

3:15 PM Phenomenology: Measuring deviations from the Kerr geometry with black hole ringdown - Kallol Dey (Indian Institute of Science Education and Research, Thiruvananthapuram)

4:00 PM Phenomenology: Constraining modifications of black hole perturbation potentials near the light ring with quasinormal modes - Sebastian Völkel (Max Planck Institute for Gravitational Physics (Albert Einstein Institute))

4:15 PM Phenomenology: Spacetime-Symmetry Breaking and the Generation of Gravitational Waves - Nils Nilsson (SYRTE, l'Observatoire de Paris)

4:30 PM Phenomenology: Test of the Second Postulate of Relativity from Gravitational Wave Observations - Sreejith Nair (Indian Institute of Technology(IIT) Gandhinagar)

4:45 PM Phenomenology: Orthogonality and transitions between black-hole quasibound states - enrico cannizzaro (La Sapienza University of Rome)

5:00 PM Phenomenology: Nonlinear photon-plasma interaction and the black-hole superradiant instability - Fabrizio Corelli ("Sapienza" University of Rome)

5:15 PM ###
Theory
Theory
2:00 PM - 5:45 PM
Room: Aula Magna, Room A, B, D
Contributions

2:00 PM Theory: Bouncing and emergent cosmology from Dark Energy with an unstable de Sitter vacuum - Marco Bruni (University of Portsmouth)

2:15 PM Theory: On the wormhole-warp drive correspondence - Kirill Zatrimaylov (Università degli Studi di Bergamo)

2:30 PM Theory: Casimir wormholes with a scalar field - Athanasios Tzikas (University of Bergamo)

2:45 PM Theory: Geometry of the black-to-white hole transition - Farshid Soltani (Western University)

3:00 PM Theory: Quantum integrable black holes - Andrea Giusti (ETH Zurich)

3:15 PM Theory: Constructing accelerating NUT black holes - José Barrientos (Universidad de Tarapacá)

4:00 PM Theory: Vacuum entanglement in near extremal black holes - Salvatore Ribisi (Centre de Physique Théorique - Marseille)

4:15 PM Theory: Hawking Radiation without Lorentz Invariance - Francesco Del Porro (SISSA)

4:30 PM Theory: Noncommutative Correction to Black Hole Entropy - Filip Požar

4:45 PM Theory: Renormalization and untarity in an higher derivative scalar theory - Diego Buccio (SISSA, INFN)

5:00 PM Theory: Mapping the landscape of gravity theories - Serena Giardino (Max Planck Institute for Gravitational Physics & Heidelberg University)

5:15 PM Theory: Self gravity affects quantum states - David Edward Bruschi (Institute for Quantum Computing Analytics (PGI-12), Forschungszentrum Jülich)

5:30 PM Theory: Aspects of kinetic screening - UV completion and the two-body problem - Mateja Boskovic (SISSA)
8:00 PM Social Dinner+Jazz Concert
Social Dinner+Jazz Concert
8:00 PM - 11:00 PM
Friday, September 8, 2023
9:00 AM Tests of theories of gravitation in their weak-field and slow-motion limit with laser-tracked satellites - David Lucchesi (INFN Roma Tor Vergata; IAPS/INAF Tor Vergata)
Tests of theories of gravitation in their weak-field and slow-motion limit with laser-tracked satellites
- David Lucchesi (INFN Roma Tor Vergata; IAPS/INAF Tor Vergata)
9:00 AM - 10:00 AM
Room: Aula Magna The geodynamic satellites LAGEOS (NASA, 1976), LAGEOS II (ASI/NASA, 1992) and LARES (ASI, 2012) were taken as test masses and their motions were carefully studied and compared with that of a time-like geodesic of General Relativity (GR). This allowed to obtain a series of significant results in the study of the gravitational interaction in the so-called weak-field and slow-motion (WFSM) limit of GR. In this limit, Einstein’s equations reduce to a form quite similar to those of electromagnetism, with a gravitoelectric field produced by masses, analogous to the electric field produced by charges, and a gravitomagnetic field produced by mass-currents, analogous to the magnetic field produced by electric currents. These fields are at the origin of two non-classical precessions of the orbit of an artificial satellite. The first precession is due to the mass of the Earth, it is known as Schwarzschild’s or Einstein’s precession of the orbit. This is a spin-independent secular precession. The second precession is due to the angular momentum (or spin) of the Earth, it is known as the Einstein-Thirring-Lense secular precession of the orbit. The latter is a spin-orbit effect, also known as frame-dragging, and it is related with intrinsic gravitomagnetism. The precise and accurate measurement of these two precessions has not only allowed to verify the predictions of the GR but also to place significant constraints on the predictions of some alternative theories of gravitation. These theories may be both metric and non-metric in their consequences. A very interesting aspect in the verification of the gravitational interaction is represented by the possible existence of new long-range interactions. This kind of effect in gravitation has some importance since it cannot be interpreted within the standard Parametrized Post-Newtonian (PPN) formalism currently used in the WFSM limit of GR. Indeed, deviations of the gravitational potential from the Newtonian law would lead to new weak interactions between macroscopic objects that are predicted by several theories of gravity. For these theories, a Yukawa-like parameterization seems general at the lowest order of the interaction and in the non-relativistic limit, independently of the nature of the new field that contributes to mediate the gravitational interaction, that is, of a possible scalar, vector or tensor field. As already underlined, the main goal is to verify the motion of each test mass along a geodesic of spacetime by means of a very precise determination of their orbits. In this regard, the challenge is represented by a reliable modeling of the main gravitational and non-gravitational perturbations (NGPs) acting on the considered satellites. Indeed, both types of perturbations can have a negative impact in the measurements. Mismodeling of gravitational perturbations, especially of the even zonal harmonic coefficients, can completely mask the tiny relativistic precessions due to GR because of their much larger classical precession of the orbit. Conversely, NGPs are very complicated to model and have a periodic impact in the orbital elements, with very long period perturbations superimposed on the relativistic precessions making their measurement extremely complicated. Some of these activities were carried out in a previous experiment called LARASE (LAser RAnged Satellite Experiment, 2013-2019), while others are currently performed in a new experiment called SaToR-G (Satellite Test of Relativistic Gravity), both funded by the National Scientific Committee 2 (CSN2) of the National Institute for Nuclear Physics (INFN). The results achieved by the two experiments will be presented in the measurement of the main relativistic precessions in the orbits of the satellites together with the consequent limits obtained in several theories of gravitation alternative to GR. These constraints may concern metric theories of gravitation  such as scalar-tensor theories  and non-metric theories of gravitation  such as torsional theories. Finally, the prospects for ongoing and future measurements of the gravitational interaction in the field of the Earth with laser-ranged satellites will be presented.
10:00 AM Coffe Break
Coffe Break
10:00 AM - 10:30 AM
10:30 AM The black hole mass function and merger rate across cosmic time - Michela Mapelli
The black hole mass function and merger rate across cosmic time
- Michela Mapelli
10:30 AM - 11:30 AM
Room: Aula Magna With nearly one hundred gravitational-wave events observed by LIGO and Virgo, the mass function of binary black holes starts revealing a number of features. While the most common primary black hole mass is about 8-10 Msun, the data show an excess at ~35 Msun and a long tail extending out to 90 Msun. Such features must encode the formation history of binary black holes, but their analysis has brought us more questions than answers. In my talk, I discuss several possible scenarios for the emergence of these features, based on novel semi-analytic models of binary evolution and star cluster dynamics. Furthermore, I will show that the merger rate density of binary black holes contains crucial information to explain the formation of such extreme systems as a function of redshift. In particular, metal-poor and metal-free stars are the key progenitors of binary black hole mergers in the early Universe, which will be the target of next-generation ground-based detectors.
11:30 AM Gravitational charges on null hypersurfaces - Simone Speziale
Gravitational charges on null hypersurfaces
- Simone Speziale
11:30 AM - 12:30 PM
Room: Aula Magna We review the Wald-Zoupas prescription for gravitational charges at future null infinity, and its recent application to null hypersurfaces at finite distance and to non-expanding horizons. We highlight the importance of anomalous transformations in the phase space introduced by background structures, and how they help explaining a tricky step in the original Wald-Zoupas paper, clarify the relation between those charges and Noether charges, and enter the flux-balance laws of gravitational waves. We then present a modified set of charges at finite distance with better conservation properties, and comment on proposed extensions of the phase space at future null infinity and at finite distances.
12:30 PM Farewell and Lunch
Farewell and Lunch
12:30 PM - 2:00 PM

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