On-line “Newton 1665” seminars – phenomenology/theory/astro/cosmo

28 Feb 2020, 09:00 → 31 Mar 2021, 19:00 Europe/Rome

On Zoom

Since Covid-19 lockdown in March 2020 we organize on-line seminars on phenomenology/theory/astrophysics/cosmology, and whatever can be interesting in theoretical physics.  We have no fixed dates and time, see the timetable (European, CET).

If you wish to join a seminar: login at the starting time on https://cern.zoom.us/j/5876144043 using your real name and password 1665. In case of trouble: see instructions.

Video recordings of most seminars are available on the YouTube channel "Newton 1665 physics seminars ."

If you wish to receive announcements of future seminars: add your email to the mailing list https://groups.google.com/forum/#!forum/physem/join. 

If you wish to suggest seminars and/or help organizing: email to organizers (on-line-newton-seminars@googlegroups.com).

 

Timetable of fundamental physics webinars worldwide (see also inspires).

Friday 28 February

15:00 → 15:30 A Critique of the Asymptotic Safety Program

https://arxiv.org/abs/1911.02967

Speaker: John Donoghue (University of Massachusetts, Amherst)

15:30 → 16:00 Precarious Naturalness

I will discuss a novel solution to the hierarchy problems, both for the Higgs mass and the cosmological constant. The only new ingredient is an ultra-light scalar coupled to the Higgs in the presence of heavier new physics. This works at the price of making the Universe itself precarious.
https://arxiv.org/abs/2002.02463

Speaker: Daniele Teresi (Università di Pisa)

teresi_precarious_naturalness.pdf

Thursday 12 March

15:00 → 15:30 Probing the scale of grand unification with gravitational waves

Talk based on https://arxiv.org/pdf/1912.03695.pdf

Speaker: Dr Valerie Domcke (Deutsches Elektronen-Synchrotron DESY)

GUTs and GWs - domcke.pdf

15:30 → 16:00 CMB bounds on primordial black holes (including dark matter halo accretion)

Talk based on https://arxiv.org/abs/2002.10771

Speaker: Pasquale Dario Serpico (CNRS, Laboratoire d'Annecy-le-Vieux de Physique Théorique (LAPTh), France)

1665_serpico.pdf

Saturday 14 March

15:00 → 15:50 Accessing the QCD conformal window with perturbation theory and beyond

Review talk on the role and properties of asymptotic expansions in quantum field theory. The results of https://arxiv.org/abs/2003.01742 will be also presented and discussed.

Speaker: Marco Serone (TS)

Webinar_Serone_2.pdf

Monday 16 March

11:30 → 12:00 Annual modulations from secular variations: relaxing DAMA?

Talk based on https://arxiv.org/abs/2002.00459

Speaker: Dario Buttazzo (Universität Zürich)

DAMA.pdf

12:00 → 12:30 Annual modulations from secular variations: not relaxing DAMA?

Talk based on https://arxiv.org/abs/2003.03340

Speaker: Andrea Messina (ROMA1)

slides-2003.03340.pdf

Friday 20 March

14:00 → 14:50 Crunching away the Cosmological Constant problem

Talk based on https://arxiv.org/pdf/1912.08840.pdf

Speaker: Tomer Volansky (Tel-Aviv University)

CC.Italy-Remove.30-50min.pdf

Sunday 22 March

13:00 → 13:50 Entropy Bound and Unitarity of Scattering Amplitudes

Talk based on https://arxiv.org/abs/2003.05546v1

Speaker: Prof. Georgi Dvali (Max Planck-Institut fur Physik, Munchen, Germany)

Entropy_online_seminar_April_2_corr.pdf

Thursday 26 March

15:00 → 15:30 Physics beyond the standard model from Higgs Parity

The discovery of the Higgs boson has revealed that the quartic Higgs self-coupling becomes small at very high energy scales. Guided by this observation, We introduce Higgs Parity, which is a spontaneously broken symmetry exchanging the standard model Higgs with its parity partner. In addition to explaining the small Higgs quartic coupling, Higgs Parity can provide a dark matter candidate, solve the strong CP problem, and arise from an SO(10) grand unified gauge symmetry. We will show that the Higgs Parity symmetry breaking scale is determined by standard model parameters and predicts experimental signals such as the dark matter direct detection rate and the proton decay rate. As a result, Higgs Parity provides a tight correlation between future precision measurements of standard model parameters and these experimental signals.

Based on:
https://arxiv.org/abs/1803.08119
https://arxiv.org/abs/1902.07726
https://arxiv.org/abs/1905.12722

Speaker: Keisuke Harigaya (IAS, Princeton)

2020Newton.pdf

15:30 → 16:00 Axiogenesis

We proposed a mechanism called axiogenesis to explain the observed cosmological excess of matter over antimatter. A rotation of the QCD axion is induced by explicit Peccei-Quinn symmetry breaking in the early universe. The rotation corresponds to the asymmetry of the PQ charge, which is converted into the baryon asymmetry via QCD and electroweak sphaleron transitions. The concrete model we explore predicts a small decay constant and has close connections with axion dark matter and new physics at the colliders.

Talk based on:
https://arxiv.org/pdf/1910.02080.pdf
https://arxiv.org/pdf/1910.14152.pdf

Speaker: Raymond Co (U. Michigan)

Axiogenesis.pdf

Sunday 29 March

11:30 → 12:00 Dark matter from scalar field fluctuations

https://arxiv.org/abs/1905.01214

Speaker: Dr Tommi Tenkanen (Department of Physics and Astronomy, Johns Hopkins University)

Tommi_Tenkanen_Newton1665.pdf

12:00 → 12:30 Axion Dark Matter Detection by Superconducting Resonant Frequency Conversion

http://arxiv.org/pdf/1912.11048.pdf

Speaker: Raffaele D'Agnolo

Friday 3 April

15:00 → 15:30 Gravitational Waves from Supercool Axions

Speaker: Luigi Delle Rose (FI)

DelleRose-Newton.pdf

15:30 → 16:00 Axing minimal pre-inflationary axion models

Speaker: Carlos Tamarit (Munich, Tech. U.)

Axing_axions_Netwon1665.pdf

Sunday 5 April

16:00 → 16:50 Dark Matter Waves

A dark matter particle lighter than about 100 eV is expected to exhibit wave behavior in
a galaxy like the Milky Way. We discuss particle physics motivations for such a scenario, and
implications for astrophysical observations and experimental detection.

Talk based on
https://arxiv.org/abs/2004.01188
https://arxiv.org/abs/1904.12803
https://arxiv.org/abs/1810.01915
https://arxiv.org/abs/1610.08297

Speaker: Prof. Lam Hui (Columbia U.)

Newton1665_2020.pdf

video

Friday 10 April

11:30 → 12:00 Leading-order hadronic vacuum polarization contribution to the muon magnetic momentfrom lattice QCD

https://arxiv.org/abs/2002.12347

Speaker: Kalman Szabo (University of Wuppertal)

12:00 → 12:30 Hadronic vacuum polarization: (𝑔−2)𝜇 versus global electroweak fits

https://arxiv.org/abs/arXiv:2003.04886

Speaker: Andreas Crivellin (UZH&PSI)

Crivellin.pdf

Sunday 12 April

16:00 → 16:30 Parametric resonance of photons in axion backgrounds

Based on https://arxiv.org/abs/1911.07885

Speaker: Gonzalo Alonso-Álvarez (U. Heidelberg, ITP)

Newton1665_Gonzalo_Alonso_Alvarez.pdf

video

16:30 → 17:00 The large misalignment mechanism: Formation and signatures of compact axion structures

Based on https://arxiv.org/abs/1909.11665

Speaker: Jedidiah O. Thompson (Stanford U., ITP)

2020-4_Thompson.pdf

Thursday 16 April

15:00 → 15:40 Standard Model Meets Gravity: Electroweak Symmetry Breaking and Inflation

https://arxiv.org/abs/2001.09088

Speaker: Prof. Mikhail Shaposhnikov (The École polytechnique fédérale de Lausanne (EPFL))

Newton2020_goodnotes.pdf

video

15:40 → 16:10 Non-Gaussianities and tensor-to-scalar ratio in non-local R^2-like inflation

https://arxiv.org/abs/2003.00629

Speaker: Alexey Koshelev (Universidade da Beira)

video

Thursday 23 April

17:00 → 17:30 Metastable nuclear isomers as Dark Matter accelerators

https://inspirehep.net/literature/1742085

Speaker: Maxim Pospelov

video

17:30 → 18:00 Exploring light dark matter with atomic clocks and magnetometers

In this talk I’ll introduce some ideas to use atomic clocks and co-magnetometers for direct detection of light dark matter candidates. I will describe the leading effects on the devices from scattering with dark matter particles, valid for all dark matter masses below MeV. If time permits, I will also discuss other phenomena happening for ultra-light dark matter candidates.

Speaker: Diego Blas (King's college)

2005Newton_Blas.pdf

video

Sunday 26 April

15:00 → 15:30 Understanding very strong electroweak phase transitions

https://arxiv.org/abs/2001.00568
https://arxiv.org/abs/1904.01329

Speaker: Kimmo Kainulainen

video

15:30 → 16:00 Phase transitions in perturbative walking dynamics

https://arxiv.org/abs/2003.10265

Speaker: Aleksandr Azatov (Istituto Nazionale di Fisica Nucleare)

newton_aa.pdf

video

Thursday 30 April

15:00 → 15:30 EeV dark matter in the early Universe

https://arxiv.org/abs/2003.02846

Speaker: Yann Mambrini (Université Paris-Saclay)

video

15:30 → 16:00 Black Hole Shadows and New Physics

https://arxiv.org/abs/2001.02986

Speaker: Luca Visinelli (Stockholm University & Nordita)

M87_Shadow.pdf

video

Sunday 3 May

16:00 → 16:30 New ’t Hooft anomalies and phases of gauge theories

https://inspirehep.net/literature/1731548
https://inspirehep.net/literature/1755073
https://inspirehep.net/literature/1755641

Speaker: Erich Poppitz (Toronto U.)

PoppitzNewton1665.pdf

video

16:30 → 17:00 New ’t Hooft anomalies and phases of chiral gauge theories

https://inspirehep.net/literature/1754164
https://inspirehep.net/literature/1738293
https://inspirehep.net/literature/1791206

Speaker: Kenichi Konishi (Univ. Pisa and INFN, Pisa)

KonishiNewton1665.pdf

video

Thursday 7 May

15:00 → 15:30 Rethinking Superdeterminism 1

https://arxiv.org/abs/1912.06462

Speaker: Sabine Hossenfelder (Frankfurt Institute for Advanced Studies)

Hossenfelder.pdf

video

15:30 → 16:00 Rethinking Superdeterminism 2

https://arxiv.org/abs/1912.06462

Speaker: Timothy N. Palmer (Oxford Phys. Dept.)

Palmer.pdf

Friday 8 May

15:00 → 16:00 The Cellular Automaton Interpretation of Quantum Mechanics.

https://arxiv.org/abs/1405.1548
https://inspirehep.net/literature/1796219

Speaker: Gerard 't Hooft (Utrecht U.)

CA-QM-CERN-2020.pdf

video

Sunday 10 May

18:00 → 18:50 Lessons from the Color and Kinematics of Scattering

https://inspirehep.net/literature/1782242
https://inspirehep.net/literature/1598637
https://inspirehep.net/literature/1503150

Speaker: Clifford Cheung (Caltech)

video

Friday 15 May

16:00 → 16:50 The Wolfram model

https://inspirehep.net/literature/1793601

Speaker: Dr Jonathan Gorard (University of Cambridge and Wolfram Research, Inc. )

video

Sunday 17 May

17:00 → 17:30 Electroweak-Symmetric Dark Monopoles from Preheating

https://inspirehep.net/literature/1793864

Speaker: Nicholas Orlofsky

NO_EWSDarkMonopoles.pdf

video

17:30 → 18:00 Macroscopic dark matter: models and detections

https://inspirehep.net/literature/1788678
https://inspirehep.net/literature/1768642

Speaker: Yang Bai

MDM_YangBai.pdf

video

Sunday 24 May

17:00 → 18:00 Strings, Particle Physics and the Swampland

Speaker: Luis Ibañez (UAM)

ZoomJune2020.pdf

Friday 29 May

17:30 → 18:00 The Hubble Hunter's Guide

https://inspirehep.net/literature/1748842

Speaker: Marius Millea (Berkeley)

18:00 → 18:30 Attempting to alleviate the H0 tension with physically motivated models

https://inspirehep.net/literature/1790840 etc
https://inspirehep.net/literature/1689395 etc

Speaker: Alessio Notari (Universitat de Barcelona)

18:30 → 18:50 The Hubble-Penzias-Wilson tension

https://inspirehep.net/literature/1797294

Speaker: Yacine Ali-Haimoud (NYU)

Sunday 31 May

16:00 → 16:30 Flavor Phenomenology of the QCD axion and axion like particles

https://inspirehep.net/literature/1779843
https://inspirehep.net/literature/1505751

Speaker: Jure Zupan (U. of Cincinnati)

Netwon_1665_Zupan.pdf

16:30 → 17:00 X-ray and Radio Searches for Axions from Nearby Neutron Stars

https://inspirehep.net/literature/1789227
https://inspirehep.net/literature/1758450
https://inspirehep.net/literature/1724844
https://inspirehep.net/literature/1667821

Speaker: Ben Safdi (U. Michigan)

Neutron stars as axion laboratories.pdf

Friday 5 June

17:00 → 17:30 λϕ4 in de Sitter

https://inspirehep.net/literature/1762612

Speaker: Leonardo Senatore (Stanford University)

seminar_lambdaphi4_PisaTriesteFirenze_v5.pdf

17:30 → 18:00 De Sitter Diagrammar and the Resummation of Time

https://inspirehep.net/literature/1772081

Speaker: Matthew Baumgart (Arizona State University)

dsHolographySISSA.pdf

Sunday 7 June

10:00 → 10:30 Primordial magnetic fields: origin and evolution

https://inspirehep.net/literature/1691821
https://inspirehep.net/literature/1724093

Speaker: Dr Takeshi Kobayashi (Nagoya University)

10:30 → 11:00 Detecting light boson dark matter through conversion into a magnon

https://inspirehep.net/literature/1777759

Speaker: Prof. Takeo Moroi (University of Tokyo and Kavli IPMU)

Thursday 11 June

16:00 → 16:30 Building blocks for gravity

https://inspirehep.net/literature/1681049

Speaker: Lavinia Heisenberg

16:30 → 17:00 Dark energy after gravitational wave observations

https://inspirehep.net/literature/1762375
https://inspirehep.net/literature/1693361
https://inspirehep.net/literature/1630859

Speaker: Filippo Vernizzi

Newton_1665.pdf

Sunday 14 June

17:00 → 17:30 Towards a Phenomenology for the non-supersymmetric Heterotic String

https://inspirehep.net/literature/1343824

Speaker: Steven Abel (Durham U., IPPP)

17:30 → 18:00 On vacuum stability in non-supersymmetric strings

https://inspirehep.net/literature/1749295
https://inspirehep.net/literature/1742999
https://inspirehep.net/literature/1705684
https://inspirehep.net/literature/1639838

Speaker: Ivano Basile (SNS)

Thursday 18 June

10:00 → 11:20 Theoretical interpretations of the Xenon anomaly (EurAsia time-zone)

Video of all talks

10:00 Inelastic Dark Matter Electron Scattering and the XENON1T Excess

https://arxiv.org/abs/2006.11938

Speaker: Motoo Suzuki

motoo_suzuki.pdf

10:10 Dark Matter and the XENON1T electron recoil excess

http://arxiv.org/abs/2006.10735

Speaker: Hardi Veermae

X1T_FastDM.pdf

10:20 Boosted Dark Matter and Sun-Heated DM

https://arxiv.org/abs/2006.12447 and https://arxiv.org/abs/2006.11264

Speaker: Jing Shu

XENON1T.pdf

10:32 XENON1T anomaly from anomaly-free ALP dark matter and its implications for stellar cooling anomaly

https://arxiv.org/abs/2006.10035

Speaker: Wen Yin

slide_WenYin.pdf

10:42 Exploring New Physics with O(keV) Electron Recoils in Direct Detection Experiments

https://arxiv.org/abs/2006.14521

Speaker: Itay M. Bloch

10:52 Hidden Photon Dark Matter in the Light of XENON1T and Stellar Cooling

https://arxiv.org/abs/2006.11243

Speaker: Lennert Thormaehlen

XENON1T-Newton.pdf

17:00 → 18:30 Theoretical interpretations of the Xenon anomaly (EurAmerica time-zone)

17:00 Co-SIMP Miracle (Xenon as DM DM e -> DM e)

https://arxiv.org/abs/2002.04038

Speaker: Juri Smirnov

Co-SIMP-10-min.pdf

17:10 Solar axions cannot explain the XENON1T excess

https://arxiv.org/abs/2006.12487

Speaker: Marco Fedele

Newton1665_Fedele.pdf

17:20 Re-examining the Solar Axion Explanation for the XENON1T Excess

https://arxiv.org/abs/2006.14598

Speaker: Wei Xue

invPrim.pdf

17:30 Shining dark matter in Xenon1T

https://arxiv.org/abs/2006.12462

Speaker: Michele Tammaro

X1T_Tammaro.pdf

17:40 New limits on dark photons from solar emission and keV scale dark matter

https://inspirehep.net/literature/1802729

Speaker: Josef Pradler

17:50 Light new physics in XENON1T (solar neutrinos with anomalous couplings)

https://arxiv.org/abs/2006.11250

Speaker: Aaron C. Vincent

NewtonXenonAaron.key

18:00 Concluding remarks

Speaker: Maxim Pospelov

Newton2020_Xenon.pdf

Sunday 21 June

17:00 → 17:30 On Merger of Axion Dark Matter Clumps and Parametric Resonance of Photons

https://inspirehep.net/literature/1794475
https://inspirehep.net/literature/1776696
https://inspirehep.net/literature/1670964
https://inspirehep.net/literature/1668954
https://inspirehep.net/literature/1630599

Speaker: Enrico Schiappacasse (Jyväskylä University & Helsinki Institute of Physics)

EnricoDSchiappacasse_Netwon1665.pdf

17:30 → 18:00 Detecting Axion Dark matter with collective excitations

https://inspirehep.net/literature/1797239
https://inspirehep.net/literature/1759702
https://inspirehep.net/literature/1737603

Speaker: Andrea Mitridate (INFN)

AxionDetection.pdf

Thursday 25 June

15:00 → 15:30 Can negative kinetic energy be physically acceptable?

https://inspirehep.net/literature/1806563
Talk on youtube

Speaker: Alessandro Strumia (PI)

Strumia.pdf

Video

15:30 → 16:00 Predictions on inflationary cosmology from quantum gravity with purely virtual quanta

https://inspirehep.net/literature/1797245
https://inspirehep.net/literature/1677293
https://inspirehep.net/literature/1663463

Speaker: Marco Piva (NICPB)

NewtonSeminarPiva.pdf

Video

16:00 → 16:30 Ghost Problems from Pauli-Villars to Fourth-Order Quantum Gravity and their Resolution

https://inspirehep.net/literature/1789233

Speaker: Philip D. Mannheim (University of Connecticut)

Video

Friday 10 July

17:00 → 17:30 Probing Dark Photons with Plasma Haloscopes

https://inspirehep.net/literature/1800931

Speaker: Volodymyr Takhistov

Takhistov.pdf

17:30 → 18:00 Searching for Dark Photon DM with Gravitational Wave Detectors

https://inspirehep.net/literature/1734427

Speaker: Fengwei Yang

Fengwei.pdf

Sunday 12 July

17:00 → 17:30 Gravitational particle production in the Inflationary Era 1

https://inspirehep.net/literature/1706238
https://inspirehep.net/literature/1616062
https://inspirehep.net/literature/664609
https://inspirehep.net/literature/1358647

Speaker: Rocky Kolb

Newton_1665.pdf

Video

17:30 → 18:00 Gravitational particle production in the inflationary Era 2

Speaker: Andrew Long

Thursday 16 July

15:00 → 15:30 Overview of Standard BBN and the Primordial Lithium Problem

https://inspirehep.net/literature/1084757
https://inspirehep.net/literature/1122491
https://inspirehep.net/literature/1768194
https://www.youtube.com/watch?v=XbzvlFRoKrw

Speaker: Brian Fields (Departments of Astronomy and of Physics, University of Illinois)

BDFields_BBNLiProblem_Newton1665.pdf

Video

15:30 → 16:00 New Physics solutions to the lithium problem

https://inspirehep.net/literature/859174
https://inspirehep.net/literature/1402055
https://www.youtube.com/watch?v=NI0Y00SiLHw

Speaker: Josef Pradler

2020OnlineNewtonLithium-2.pdf

Video

Friday 17 July

15:00 → 15:30 Absence of CP violation in the strong interactions

https://inspirehep.net/literature/1776674
The CP-odd theta-term that should be assumed to be nonzero in general requires an explanation why it does not lead to CP-violating observables in the strong interactions. Known approaches include vanishing quark masses or extensions of the Standard Model. Here, we construct the fermionic Green's and correlation functions in the background of an instanton gas. For these correlators, we find that the CP-odd phases in the terms that break chiral symmetry from the quark masses and from the instanton effects are aligned, such that there remain no CP-violating observables. Crucial for this conclusion is that in the calculation of the correlators, the spacetime volume has to be taken to infinity before summing over the topological sectors.

The absence of CP-violation in strong interactions is therefore explained within the Standard Model.

Speaker: Bjorn Garbrecht (Munich, Tech. U.)

seminar_bg_280720.pdf

video

15:30 → 16:00 θ dependence of 4D SU(N) gauge theories in the large-N limit

https://inspirehep.net/literature/1477409

Speaker: Claudio Bonati (UniPi)

Video

16:00 → 16:30 More Axions from Strings

https://inspirehep.net/literature/1806488

The axion solution to the strong CP problem also provides a natural dark matter candidate. If the PQ symmetry has ever been restored after inflation, topological defects of the axion field would have formed and produced relic axions, whose abundance is in principle calculable. We study the contribution to the abundance produced by string defects during the so-called scaling regime. Clear evidence of scaling violations is found, the most conservative extrapolation of which strongly suggests a large number of axions from strings. The overall result is a lower bound on the QCD axion mass in the post-inflationary scenario that is substantially stronger than the naive one from misalignment.

Speaker: Marco Gorghetto (Weizmann)

video

Saturday 29 August

16:00 → 17:00 Magnetic black holes and traversable wormholes

We will discuss the physics of magnetically charged black holes. If we have charged massless fermions, there is a large number of effectively two-dimensional fields that give rise to interesting effects. An interesting effect is that they lead to a controllable construction of traversable wormholes without the addition of exotic matter. For the matter of the Standard Model, these wormholes are microscopic. On the other hand, with matter described by a suitable version of the Randall-Sundrum model, they could be traversed by a human.

https://inspirehep.net/literature/1811920
https://inspirehep.net/literature/1790955
https://inspirehep.net/literature/1681998

Speaker: Prof. Juan Maldacena (IAS)

Video

Thursday 3 September

17:00 → 17:30 The Black hole firewall paradox

Speaker: David Kaplan (Johns Hopkins U.)

video

17:30 → 18:00 Firewalls in General Relativity

https://inspirehep.net/literature/1706214
https://inspirehep.net/literature/1809495

We present spherically symmetric solutions to Einstein’s equations, which are equivalent to canonical Schwarzschild and Reissner-Nordstrom black holes on the exterior, but with singular (Planck-density) shells at their respective event and inner horizons. The locally measured mass of the shell and the singularity are much larger than the asymptotic Arnowitt-Deser-Misner mass. The area of the shell is equal to that of the corresponding canonical black hole, but the physical distance from the shell to the singularity is a Planck length, suggesting a natural explanation for the scaling of the black hole entropy with area. The existence of such singular shells enables solutions to the black hole information problem of Schwarzschild black holes and the Cauchy horizon problem of Reissner-Nordstrom black holes. While we cannot rigorously address the formation of these solutions, we suggest plausibility arguments for how “normal” black hole solutions may evolve into such states. We also discuss the stability of these structures.

Speaker: Surjeet Rajendran (Johns Hopkins U.)

Newton Seminar.pdf

video

Sunday 6 September

17:30 → 18:00 The muon g-2 anomaly and Δα connection

https://inspirehep.net/literature/1800513
https://inspirehep.net/literature/1802519

Speaker: Massimo Passera

Passera_17092020.pdf

Video

18:00 → 18:30 The Neutron Bottle Anomaly and a Composite Solution

https://inspirehep.net/literature/1811764

Speaker: Harikrishnan Ramani

Hari_Newton1665.pdf

Video

Friday 11 September

15:00 → 15:50 Euclidean wormholes, baby universes, and their impact on particle physics and cosmology

https://inspirehep.net/literature/1680679

Speaker: Arthur Hebecker (Heidelberg U.)

Slides

Video

Friday 18 September

15:30 → 16:15 Supermassive black hole astrophysics with pulsar timing arrays: a critical view of the recent NANOGrav analyisis

Speaker: Prof. Alberto Sesana (University of Milan Bicocca)

Video

16:15 → 16:30 On cosmological interpretations of the NANOGrav result

Speaker: Dr Ville Vaskonen (IFAE, Universitat Autonoma de Barcelona)

Video

Thursday 1 October

16:00 → 16:45 An excess of small-scale gravitational lenses observed in galaxy clusters

Thanks to the recent CLASH and Frontier Fields programs of the Hubble Space Telescope, it has been possible to identify an unprecedented number of strong lensing features (multiple images and gravitational arcs) in the fields of several galaxy clusters.

We used these features in combination with MUSE spectroscopic observations to recover the mass distribution in the cluster cores. The mass models show that the cross-section for galaxy-galaxy strong lensing in these clusters is large. This is confirmed by the detection of several lensing events where the lens is a cluster member. With the aid of numerical simulations, we compare these observations to theoretical expectations in the framework of the LCDM model.

We show that clusters obtained from state-of-the-art N-body and hydrodynamical simulations have cross-sections for galaxy-galaxy strong lensing ~10 times smaller than measured in observations. At given mass, observed subhalos are stronger lenses because they are more compact than their simulated analogs. They also tend to be more concentrated towards the center of the cluster.

We suggest that hitherto undiagnosed systematic issues with simulations or incorrect assumptions about the properties of dark matter could explain our results.

Speaker: Dr Massimo Meneghetti (INAF)

Sunday 4 October

17:00 → 17:30 Signals of the QCD axion with mass of 17 MeV

https://inspirehep.net/literature/1816996

Speaker: Prof. Daniele Alves (Los Alamos National Laboratory)

1665NewtonSeminars_Oct2020_LAUR.pdf

video

17:30 → 18:00 Dynamical evidence for a fifth force explanation of the ATOMKI anomalies

https://inspirehep.net/literature/1798918

Speaker: Dr Christopher Verhaaren (University of California, Irvine)

video

Saturday 10 October

16:00 → 16:30 Witnessing Quantum gravity via Entanglement of Masses

Understanding gravity in the framework of quantum mechanics is one of the great challenges in modern physics. Along this line, a prime question is to find whether gravity is a quantum entity subject to the rules of quantum mechanics. It is fair to say that there are no feasible ideas yet to test the quantum coherent behaviour of gravity directly in a laboratory experiment. Here, I will introduce an idea for such a test based on the principle that two objects cannot be entangled without a quantum mediator. I will show that despite the weakness of gravity, the phase evolution induced by the gravitational interaction of two micron size test masses in adjacent matter-wave interferometers can detectably entangle them even when they are placed far apart enough to keep Casimir-Polder forces at bay. I will provide a prescription for witnessing this entanglement, which certifies gravity as a quantum coherent mediator, through simple correlation measurements between two spins: one embedded in each test mass. Fundamentally, the above entanglement is shown to certify the presence of non-zero off-diagonal terms in the coherent state basis of the gravitational field modes.

Speaker: Anupam Mazumdar (University of Groningen)

Mazumdar-1665.pdf

Video

16:30 → 17:00 Varying fundamental constants, from alpha to omega

The observational evidence for the recent acceleration of the universe shows that canonical theories of cosmology and particle physics are incomplete, and that new physics is waiting to be discovered. A key task for astrophysical facilities is to search for, identify and ultimately characterize this new physics. I will discuss recent developments in tests of the stability of nature's fundamental constants, which provide a direct handle on new physics. I will summarize the theoretical context and expectations, the latest observational constraints, and some implications for dark energy models. Time permitting I will also briefly highlight the gains in sensitivity expected from next-generation facilities.

Speaker: Carlos Martins (CAUP)

1665NewtonSeminars_Oct2020.pdf

Video

Monday 12 October

16:00 → 16:40 A test of the cosmological principle

The standard model of cosmology assumes that the universe is statistically isotropic & homogeneous when averaged on scales exceeding ~100 Mpc. That the CMB in fact exhibits a large dipole anisotropy is explained as due to our motion because of local inhomogeneity. This kinematic interpretation requires that there be a corresponding dipole in the sky distribution of high redshift objects. Using a new all-sky catalogue of 1.3 million quasars we find that this hypothesis is rejected at nearly 4σ by the observed matter dipole. This calls into question the usual practice of boosting to the `CMB frame' to analyse cosmological observations. In particular the acceleration of the Hubble expansion rate is also anisotropic in our heliocentric frame; it can no longer be convincingly argued that this can be made to look isotropic in the CMB frame and thus interpreted as due to Λ.
https://arxiv.org/abs/2009.14826
https://arxiv.org/abs/1912.04257
https://arxiv.org/abs/1808.04597

Speaker: Subir Sarkar (University of Oxford)

Newton1665_Sarkar_CosmoPrinciple.pdf

video

16:40 → 17:00 A test of the cosmological principle, constructive criticism

Speaker: Dominik J. Schwarz (Bielefeld University)

Thursday 15 October

15:00 → 15:30 Topological Gravity as the Early Phase of our Universe - 1

Speaker: Cumrun Vafa (Harvard)

video

15:30 → 16:00 Topological Gravity as the Early Phase of our Universe - 2

Speaker: Georges Obied (Harvard)

Sunday 18 October

16:00 → 16:30 Electroweak axion string and superconductivity

Speaker: Yu Hamada(Kyoto)

video

16:30 → 17:00 Axion strings are superconducting

Speaker: Hajime Fukada (Berkeley)

video

Thursday 12 November

16:00 → 16:30 Updates from TDCOSMO

https://inspirehep.net/literature/1805537
https://arxiv.org/abs/2008.11724

Speaker: Dr Simon Birrer (Stanford University)

video

16:30 → 17:00 Could quasar lensing time delays hint to a core component in halos, instead of H0 tension?

https://inspirehep.net/literature/1776667

Speaker: Dr Kfir Blum (Weizmann Institute of Science)

video

Sunday 15 November

16:00 → 16:40 Do we need to go beyond Cold Dark Matter?

Speaker: Prof. Andrea Macciò (NYUAD)

video

16:40 → 17:00 Self-gravitating dark matter gets in shape

https://inspirehep.net/literature/1778545
https://inspirehep.net/literature/1796967

Speaker: Dr Jenny Wagner (Heidelberg Center of Astronomy)

video

Friday 20 November

16:00 → 16:30 Positive Moments for Scattering Amplitudes

https://inspirehep.net/literature/1827503

Speaker: Francesco Riva (EPFL)

video

16:30 → 17:00 S-matrix Bootstrap for Effective Field Theories: Massless Pions

https://inspirehep.net/literature/1828526

Speaker: Joao Penedones (EPFL)

video

Thursday 26 November

17:00 → 17:40 MOND - theoretical motivations and cosmological context

https://inspirehep.net/literature/1818897
And material from https://inspirehep.net/literature/1793596

Speaker: Indranil Banik (Bonn)

CosmologyTalk_Newton1665.pdf

17:40 → 18:00 The KBC void and Hubble tension contradict ΛCDM on a Gpc scale − Milgromian dynamics as a possible solution

https://inspirehep.net/literature/1818897
For a brief summary see https://tritonstation.com/2020/10/23/big-trouble-in-a-deep-void
https://darkmattercrisis.wordpress.com

Speaker: Moritz Haslbauer (Bonn)

Friday 4 December

16:00 → 16:30 Euclidean Wormholes and their implications for the Axion quality problem

https://inspirehep.net/literature/1815818

Speaker: Miguel Escudero

Escudero_Wormholes_Newton.pdf

Video

16:30 → 17:00 Quantum Breaking of de Sitter

https://arxiv.org/abs/1701.08776
https://arxiv.org/abs/1810.11002
https://arxiv.org/abs/1811.03077
https://arxiv.org/abs/1811.03079

Speaker: Sebastian Zell

Video

Friday 1 January

14:30 → 15:00 The Weak Scale as a Trigger

https://inspirehep.net/literature/1835387

Speaker: Dr Hyung Do Kim (Seoul)

15:00 → 15:30 Direct anthropic bound on the weak scale from supernovæ explosions

https://inspirehep.net/literature/1738309

Speaker: Alessandro Strumia

Thursday 7 January

20:30 → 21:30 Rollercoaster Cosmology

https://inspirehep.net/literature/1831390

Speakers: Dr Guido D'Amico (Parma U.), Dr Nemanja Kaloper (UC Davies)

Friday 15 January

16:00 → 16:30 Strongly-Interacting Ultralight Millicharged Particles (STUMPs), and Exotic States of Matter in Dark Matter Halos

https://inspirehep.net/literature/1829805

Speaker: Evan Mcdonough (Chicago U.)

16:30 → 17:00 Resonant Self-Interacting Dark Meson and Small-Scale Structures

https://inspirehep.net/literature/1812586

Speaker: Yu-Dai Tsai (FNAL)

Thursday 4 February

15:30 → 16:00 The Emergence of Electroweak Skyrmions through Higgs Bosons

https://inspirehep.net/literature/1836507

Speaker: Juan Carlos Criado (Durham U., IPPP)

jccriado_ewskyrmion.pdf

video

16:00 → 16:30 Geometric Approaches to Quantum Field Theory: the Eisenhart Lift

https://inspirehep.net/literature/1838897

Speaker: Kieran Finn (Manchester)

eisenhart_talk.pdf

video

Monday 1 March

17:00 → 17:30 Dark Matter Direct(ional) Detection at the High Mass Frontier

https://inspirehep.net/literature/1711233
I will show that, via dedicated searches for dark matter scattering multiple times in transit, masses up to the Planck mass can be probed in current and future direct detection experiments. Moreover, this reach can be extended by a few orders of magnitude at the liquid scintillator neutrino detectors BOREXINO, SNO+, and JUNO via dedicated selection triggers. Multiscatter/track searches would also directly reconstruct the dark matter velocity distribution, hence determine the dispersion speed, escape speed, and velocity anisotropies of the Galactic halo.

Speaker: Nirmal Raj

17:30 → 18:00 Shocking Signals from CHAMP Cosmic Rays

https://inspirehep.net/literature/1711648
Cosmological relics with miniscule electric charges are well motivated in particle physics through kinetic mixing between our photon and a dark photon, and from cosmology as a way to thermally produce dark matter in the early universe. Despite their small electric charge, such thermal relics can interact with the Milky Way environment in surprising ways. I will discuss the thermalization of CHarged Massive Particles (CHAMPs) with the interstellar medium, their diffusion through inhomogeneous magnetic fields in the Milky Way, and Fermi acceleration by supernova shock waves. The Fermi accelerated CHAMPs form a component of cosmic rays that are able to reach underground detectors and produce unique experimental signatures typically absent from dark matter moving at virial speeds. I will discuss stringent bounds on the fraction of dark matter that can be CHAMPs from signals in nuclear/electron recoil experiments, ionization detectors, and Cherenkov light experiments.

Speaker: David Dunsky

Wednesday 3 March

15:00 → 15:30 TBA

15:30 → 16:00 TBA

Wednesday 10 March

15:00 → 15:30 TBA

15:30 → 16:00 TBA

Wednesday 17 March

15:00 → 15:30 TBA

15:30 → 16:00 TBA

Wednesday 24 March

15:00 → 15:30 TBA

15:30 → 16:00 TBA

Wednesday 31 March

15:00 → 15:30 TBA

15:30 → 16:00 TBA