Welcome

• Matthew Philip Mccullough (CERN)

Room: 4/3-006 - TH Conference Room

Shining axions through astrophysical walls

• Benjamin Safdi

Room: 4/3-006 - TH Conference Room

More Axion Stars from Strings

• Marco Gorghetto (DESY)

Room: 4/3-006 - TH Conference Room We show that if dark matter consists of QCD axions in the post-inflationary scenario more than ten percent of it efficiently collapses into Bose stars at matter-radiation equality. Such a result is mostly independent of the present uncertainties on the axion mass. This large population of solitons, with asteroid masses and Earth-Moon distance sizes, might plausibly survive until today, with potentially interesting implications for phenomenology and experimental searches.

Gravitational Wave-Induced Freeze-In of Fermionic Dark Matter

• Azadeh Maleknejad

Room: 4/3-006 - TH Conference Room

Where to Look and How to Look for High-Frequency Gravitational Waves

• Raffaele D'Agnolo (CEA IPhT Saclay)

Room: 4/3-006 - TH Conference Room Abstract: Stochastic backgrounds of gravitational waves can potentially open a window on extremely high energies, giving us information on phase transitions at the GUT scale and many other BSM phenomena. In this talk I will discuss simple heuristic arguments that allow to establish the smallest detectable energy density in a primordial gravitational wave background. I will focus mainly on what is achievable with realistic detectors, and comment on the potential of advanced quantum sensing techniques. In the foreseeable future, it is not feasible to go beyond the BBN bound for frequencies above 100 kHz.

Stability of Superconducting Strings

• Wei Xue (University of Florida (US))

Room: 4/3-006 - TH Conference Room

Simulating Stochastic Gravitational Waves from Early Structure Formation

• Joshua Foster (Massachusetts Institute of Technology)

Room: 4/3-006 - TH Conference Room Gravitational wave detectors provide a chance to observe the state of the very early universe and have important sensitivities for studies of early universe cosmology and searches for physics beyond the Standard Model. In this talk, I will discuss the production of potentially detectable stochastic gravitational wave backgrounds in early matter dominated eras in the linear and nonlinear regimes of structure formation.

The Strong CP Problem in String Theory (Cosmo+Swampland meeting)

• Jakob Ulrich Moritz

Room: 4/3-006 - TH Conference Room

TH colloquium by Krishna Rajagopal, "Novel Probes of the Primordial Liquid" Room: 4/3-006 - TH Conference Room Please check details on https://indico.cern.ch/event/1384507/

QCD axion strings or seeds?

• Simone Blasi (DESY)

Room: 4/3-006 - TH Conference Room

Dynamical Generation of the Baryon Asymmetry from a Scale Hierarchy

• Jae Hyeok Chang (Fermilab and UIC)

Room: 4/3-006 - TH Conference Room Abstract: We propose a novel baryogenesis scenario where the baryon asymmetry originates directly from a hierarchy between two fundamental mass scales: the electroweak scale and the Planck scale. Our model is based on the neutrino-portal Affleck-Dine (AD) mechanism, which generates the asymmetry of the AD sector during the radiation-dominated era and subsequently transfers it to the baryon number before the electroweak phase transition. The observed baryon asymmetry is then a natural outcome of this scenario. The model is testable as it predicts the existence of a Majoron with a keV mass and an electroweak scale decay constant. The impact of the relic Majoron on ΔNeff can be measured through near-future CMB observations.

Cosmological Production of ROMP Dark Matter

• David Dunsky

Room: 4/3-006 - TH Conference Room Rapidly Oscillating Massive Particles (ROMPs) arise in quantum systems with non-diagonal interaction mass matrices. This misalignment between flavor and mass eigenstates leads to oscillations such as those between electron and muon neutrinos in the Standard Model, or between active and sterile neutrinos in Beyond the Standard Model frameworks to name just a few examples. In this talk, I will discuss the general framework for dark matter production via oscillations. I will focus on ROMP systems where one flavor state, chi, is weakly coupled to the Standard Model (and hence a good dark matter candidate) and the second flavor state, psi, is strongly coupled to the Standard Model such that psi oscillations to chi in the early universe can efficiently produce chi as the dark matter. I will discuss how oscillations, scatterings, thermal masses, and resonances all play a role to give ROMPs a rich cosmology.

Axion dark matter from kinetic misalignment

• Geraldine Servant (Deutsches Elektronen-Synchrotron (DE))

Room: 4/3-006 - TH Conference Room Kinetic misalignment enables axion DM at low axion axion decay constant, which is particularly relevant for the whole experimental programme af axion searches. I’ll discuss its distinctive features such as axion fragmentation and its signatures, as well as UV implementations of rotating axions.

Probing the dark sector with Large Scale Structure

• Ennio Salvioni (University of Sussex (GB))

Room: 4/3-006 - TH Conference Room

Welcome

• Matthew Philip Mccullough (CERN)

Room: 4/3-006 - TH Conference Room

Shadow Matter

• David Kaplan

Room: 4/3-006 - TH Conference Room I will argue that there are quantum states of the field theories of general relativity and electromagnetism that we typically ignore, but have interesting phenomenological effects. These states amount to loosening the constraint equations known as the Hamiltonian and momentum constraints in GR and Gauss’ law in EM. Turning off the Hamiltonian constraint sources non-dynamical parts of the metric which mimic a pressureless dust, and thus these effects may be the explanation as to why we have inferred the existence of dark matter, both locally and cosmologically. Turning off the momentum constraints add additional velocity-dependent source terms to this effective dust, but these effects are not conserved and redshift quickly outside the horizon. Turning off the Gauss’ law constraint mimics a charge density that does not respond to electric forces, but follows geodesics, thus adding a charged component to the dust. If this new structure in the gravitational and electric fields explain dark matter, it forbids an early period of inflation and therefore requires a different explanation for density perturbations.

Continuous-Spin Particles, On Shell

• Brando Bellazzini

Room: 4/3-006 - TH Conference Room

n-shell relations between effective field theories of gluons

• Quentin Bonnefoy (DESY)

Room: 4/3-006 - TH Conference Room It is known that universal algebraic structures govern the scattering amplitudes of a large web of theories, whose boundaries are however not well understood. In this talk, I will comment on effective field theory deformations of this web. Focussing on tree-level dynamics, I will explain that the scattering amplitudes of gluons minimally coupled to adjoint scalars contain all of the information required to construct those of a tower of gluon EFTs. For instance, I will present closed-form expressions for all-multiplicity scattering amplitudes in the (CP-even) EFT of gluons at mass dimension six, and for a specific choice of Wilson coefficients at dimension eight — all constructed through a systematic and explicit recycling of dimension-four data. I will also mention how one can recursively turn spacetime dimensions into operator dimensions. The technique behind those results is our extension of the so-called covariant color-kinematics duality introduced by Cheung and Mangan.

Vignettes from Strongly-Coupled Dark Sectors

• Graham Kribs

Room: 4/3-006 - TH Conference Room I’ll discuss three recent developments related to dark glueball, dark meson, and dark baryon theory and phenomenology. Along the way we’ll see the continued importance of prompt and long-lived searches at LHC, as well as a surprising symmetry impacting dark baryon direct detection that appears in a broad class of strongly-coupled dark sectors.

Learning new tricks with the Higgs?

• Christoph Englert
• Christoph Peter Englert (University of Glasgow (GB))

Room: 4/3-006 - TH Conference Room

A different view on colliders

• Marc Riembau (CERN)

Room: 4/3-006 - TH Conference Room Energy correlators do live at the crossroads between theory and phenomenology. I will briefly review developments on both fronts that explain the resurgence of interest on these old observables. Then, I present how to compute high point correlators from recursion relations, what can be learned from low point ones, and how to go beyond energies.

Higgs Shift-Symmetries

• Javi Serra (IFT)

Room: 4/3-006 - TH Conference Room

New physics on the run from precision tests - TH colloquium

• Sophie Alice Renner (University of Glasgow (GB))

Room: 4/3-006 - TH Conference Room

Non-decoupling new particles

• David Sutherland

Room: 4/3-006 - TH Conference Room

Probing ultralight dark matter with gravity wave detectors

• Hyungjin Kim

Room: 4/3-006 - TH Conference Room

Matching EFT to LHC

• Markus Luty (University of California Davis)

Room: 4/3-006 - TH Conference Room

Non-invertible Naturalness and Quantum Flavodynamics

• Seth Koren (University of Notre Dame)

Room: 4/3-006 - TH Conference Room

Strong gauge dynamics and BSM model building tools

• Hitoshi Murayama (University of California Berkeley (US))

Room: 4/3-006 - TH Conference Room Many attractive ideas on BSM physics involve strong gauge dynamics we do not understand well. I present recent attempts to gain better understanding of strong gauge dynamics using supersymmetry and anomaly mediation of supersymmetry breaking. Then I speculate on areas of BSM model building that they may open up.

Welcome

• Tim Cohen (CERN)

Room: 4/3-006 - TH Conference Room

Talk

• T. Daniel Brennan

Room: 4/3-006 - TH Conference Room

Particle Physics meets Gravitational Wave Physics

• Jung-Wook Kim

Room: 4/3-006 - TH Conference Room I will give an overview of how quantum field theory—the main tool of particle physics—is applied to the study of relativistic two-body problem, how it is relevant to precision measurements in future gravitational wave observatories, and how it connects to my research in this topic; the effects of spin in binary dynamics.

A holographic view of the QCD axion

• Tony Gherghetta

Room: 4/3-006 - TH Conference Room

Axion couplings as UV probes

• Michael Nee (Harvard University)

Room: 4/3-006 - TH Conference Room

Geometry of Scattering Amplitudes

• Andreas Helset (CERN)

Room: 4/3-006 - TH Conference Room

Hamiltonian Truncation and Effective Field Theory

• Kara Michelle Farnsworth (Universite de Geneve (CH))

Room: 4/3-006 - TH Conference Room

On-shell techniques for the standard-model effective theory

• Gauthier Durieux (CP3 - UCLouvain)

Room: 4/3-006 - TH Conference Room

Thinking Outside the Hypercube: RS and its Implications - TH colloquium

• lisa randall (harvard)

Room: 4/3-006 - TH Conference Room

Gravitational waves from domain walls bounded by inflated cosmic strings

• Liantao Wang

Room: 4/3-006 - TH Conference Room

The quantum width of a causal diamond

• Kathryn Zurek (Caltech)

Room: 4/3-006 - TH Conference Room

Topological Portal to the Dark Sector: from EFT to UV

• Joseph Enea Davighi

Room: 4/3-006 - TH Conference Room

SU(N) and O(N) Representation Theory at non-integer N

• Xiaochuan Lu (University of California, San Diego)

Room: 4/3-006 - TH Conference Room The standard representation theory for SU(N) and O(N) groups are defined at positive integer N. However, cases of non-integer N are often encountered, e.g. when studying dimensional regularization, evanescent operators, conformal bootstrap, etc. A natural continuation to non-integer N (such as N=3.99) is to take the one at infinitely large integer N. This contains representations with arbitrarily high ranks, which must appear ("specialize") as representations with valid ranks when N is taken to be an integer. This specialization map is complicated to work out for the O(N) group. In this talk, I will introduce a very efficient new algorithm through clipping the Young diagram. I also clarify that the Racah-Speiser algorithm in textbooks is for a completely different task, which cannot achieve what our new algorithm does.

Abelian Instantons and Monopole Scattering

• Ofri Telem (The Hebrew University of Jerusalem)

Room: 4/3-006 - TH Conference Room It is usually assumed that 4D instantons can only arise in non-Abelian theories. In our recent work arXiv:2406.13738, we re-examine this conventional wisdom by explicitly constructing instantons in an Abelian gauge theory: $QED_4$ with $N_f$ flavors of Dirac fermions, in the background of a Dirac monopole. This is the low-energy effective field theory for fermions interacting with a 't Hooft-Polyakov monopole, in the limit where the monopole is infinitely heavy (hence pointlike) and static. This theory, whose non-topological sectors were studied by Rubakov and Callan, has a far richer structure than previously explored. We show how to calculate the topological instanton number, demonstrate the existence of 't Hooft zero modes localized around such instantons, and show how instantons in the path integral provide the underlying mechanism for the Callan-Rubakov process: monopole-catalyzed baryon decay with a cross-section that saturates the unitarity bound. Our computation relies on correctly identifying the relevant EFT for monopole catalysis as axial $QED_2$ in an effective $AdS_2$ metric.