We propose the experimental simulation of cosmological perturbations governed by a Planck-scale induced Lorentz violating dispersion, aimed at distinguishing between early-universe models with similar power spectra. Employing a novel variant of the scaling approach for the evolution of a Bose–Einstein condensate with both contact and dipolar interactions, we capture the hitherto unobserved phenomenon of trans-Planckian damping. We show that scale invariance, and in turn, the duality of the power spectrum is subsequently broken at large momenta for an inflating gas, and at small momenta for a contracting gas. We thereby furnish a Planck-scale sensitive approach to analogue quantum cosmology that can readily be implemented in the quantum gas laboratory.

South Korea

S. Chandran

Uwe Fischer

Expansion-contraction duality breaking in a Planck-scale sensitive cosmological quantum simulator

The Ricochet experiment aims to measure the coherent elastic neutrino-nucleus scattering process from antineutrinos emitted by a research nuclear reactor operated by the Institut Laue-Langevin (Grenoble, France). This article presents a description of the Ricochet experimental installation and the detector performance achieved during its commissioning with a mini-CryoCube module consisting of three 42-g germanium cryogenic calorimeters. The baseline resolutions and background levels are reported both during reactor-on and reactor-off periods and as noise mitigation techniques were improved. A baseline resolution of 40 eV electron equivalent was achieved for the ionization channel after setup improvements, and the phonon channel resolutions ranged from 50 to 80 eV of total phonon energy. In the energy region from 2 to 7 keV, a nuclear recoil rate of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>14</mn><mo stretchy="false">(</mo><mn>3</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>events</mi><mo>/</mo><mo stretchy="false">(</mo><mi>kg</mi><mtext> </mtext><mi>day</mi><mtext> </mtext><mtext> </mtext><mi>keV</mi><mo stretchy="false">)</mo></mrow></math> is measured during the reactor-off period selecting events in coincidence with muon veto signals. This rate is in agreement with the cosmogenic neutron rate calculated from GEANT4 simulations. After the rejection of events in coincidence with signals in the muon veto detectors, a combined 90% confidence level limit on the nuclear recoil background of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo form="prefix">&lt;</mo><mn>9</mn><mtext> </mtext><mtext> </mtext><mi>events</mi><mo>/</mo><mo stretchy="false">(</mo><mi>kg</mi><mtext> </mtext><mi>day</mi><mtext> </mtext><mi>keV</mi><mo stretchy="false">)</mo></mrow></math> is obtained in that energy region during the reactor-on period, which is compatible with our GEANT4 model calculation corresponding to a total rate of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>5</mn><mtext> </mtext><mtext> </mtext><mi>events</mi><mo>/</mo><mo stretchy="false">(</mo><mi>kg</mi><mtext> </mtext><mi>day</mi><mtext> </mtext><mi>keV</mi><mo stretchy="false">)</mo></mrow></math>. The sensitivity of this analysis was however found to be limited by a surface event contamination which is currently being addressed by the Ricochet Collaboration with upgraded detectors.

France

A. Armatol

C. Augier

L. Bailly-Salins

G. Baulieu

L. Bergé

J. Billard

J. Blé

G. Bres

J-.L. Bret

A. Broniatowski

M. Calvo

A. Cavanna

A. Cazes

United States

E. Celi

D. Chaize

M. Chala

M. Chapellier

L. Chaplinsky

G. Chemin

R. Chen

J. Colas

L. Couraud

Canada

E. Cudmore

M. De Jesus

N. Dombrowski

L. Dumoulin

A. Durnez

O. Exshaw

S. Ferriol

E. Figueroa-Feliciano

J.A. Formaggio

S. Fuard

J. Gascon

A. Giuliani

C. Goy

C. Guerin

E. Guy

L. Haegel

S.A. Hertel

C. Hoarau

Z. Hong

J.C. Ianigro

Y. Jin

A. Juillard

JINR

T. Khussainov

A. Kubik

J. Lamblin

H. Lattaud

T. Le Bellec

L. Leroy

M. Li

A. Lubashevskiy

S. Marnieros

N. Martini

J. Minet

A. Monfardini

F. Mounier

V. Novati

E. Olivieri

P.K. Patel

E. Perbet

H.D. Pinckney

D.V. Poda

D. Ponomarev

W. Van De Pontseele

J.S. Real

F.C. Reyes

A. Rodriguez

M. Rousseau

S. Rozov

I. Rozova

B. Ryan

D. Sabhari

S. Scorza

R. Serra

Ye. Shevchik

T. Soldner

A. Stutz

Ch. Ulysse

L. Vagneron

S. Vasilyev

F. Vezzu

P. Vittaz

E. Yakushev

J. Yang

D. Zinatulina

Characterization of mini-CryoCube detectors from the RICOCHET experiment commissioning at the Institut Laue-Langevin

The NUCLEUS experiment aims to detect coherent elastic neutrino-nucleus scattering of reactor antineutrinos on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>CaWO</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> targets in the fully coherent regime, using gram-scale cryogenic calorimeters. The experimental apparatus will be installed at the Chooz nuclear power plant in France, in the vicinity of two <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>4.25</mn><mtext> </mtext><mtext> </mtext><msub><mrow><mi>GW</mi></mrow><mrow><mi>th</mi></mrow></msub></mrow></math> reactor cores. This work presents results from the commissioning of an essential version of the experiment at the shallow Underground Laboratory of the Technical University of Munich. For the first time, two cryogenic target detectors were tested alongside active and passive shielding systems. Over a period of two months, all detector subsystems were operated with stable performance. Background measurements were conducted, providing important benchmarks for the modeling of background sources at the reactor site. Finally, we present ongoing efforts to upgrade the detector systems in preparation for a technical run at Chooz in 2026, and highlight the remaining challenges to achieving neutrino detection.

Austria

H. Abele

Germany

G. Angloher

B. Arnold

Italy

M. Atzori Corona

A. Bento

E. Bossio

F. Buchsteiner

J. Burkhart

F. Cappella

M. Cappelli

N. Casali

R. Cerulli

A. Cruciani

G. Del Castello

M. del Gallo Roccagiovine

S. Dorer

A. Erhart

M. Friedl

S. Fichtinger

V.M. Ghete

M. Giammei

C. Goupy

D. Hauff

F. Jeanneau

E. Jericha

M. Kaznacheeva

H. Kluck

A. Langenkämper

T. Lasserre

D. Lhuillier

M. Mancuso

R. Martin

B. Mauri

A. Mazzolari

L. McCallin

H. Neyrial

C. Nones

L. Oberauer

T. Ortmann

L. Peters

F. Petricca

W. Potzel

F. Pröbst

F. Pucci

F. Reindl

M. Romagnoni

J. Rothe

N. Schermer

J. Schieck

S. Schönert

C. Schwertner

L. Scola

G. Soum-Sidikov

L. Stodolsky

R. Strauss

R. Thalmeier

C. Tomei

M. Vignati

M. Vivier

A. Wex

Commissioning of the NUCLEUS Experiment at the Technical University of Munich

This work explores how the generalized uncertainty principle, a theoretical modification of the Heisenberg uncertainty principle inspired by quantum gravity, affects neutrino flavor oscillations. By extending the standard two-flavor neutrino model, we show that the oscillation probability acquires an additional phase term that depends on the square roots of the individual neutrino masses, introducing new features beyond the conventional mass-squared differences. To account for the non-Hermitian nature of the resulting dynamics, we employ parity-time ( <math altimg='si19.svg'><mrow><mi>P</mi><mi>T</mi></mrow></math>) symmetric quantum mechanics, which allows for consistent descriptions of systems with balanced gain and loss mechanisms. We analyze the feasibility of observing these effects in current and future neutrino experiments, such as DUNE, JUNO, IceCube, ORCA&#8211;KM3NeT, MINOS, Daya Bay, Hyper-Kamiokande, and KATRIN, and find that the predicted modifications could fall within the sensitivity of current experiments. Moreover, we propose that analog quantum simulation platforms, such as cold atoms, trapped ions, and photonic systems, offer a promising route to test these predictions under controlled conditions. Our findings suggest that neutrino oscillations may serve as an effective probe of quantum gravity effects, providing a novel connection between fundamental theory and experimental observables.

India

Kartik Joshi

Sanjib Dey

Satyajit Jena

Probing Planck scale effects on absolute mass limit in neutrino flavor evolution

We investigate whether quantum gravity fluctuations can break chiral symmetry for fermions that are charged under a U(1) and an <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>SU</mi><mo stretchy="false">(</mo><msub><mrow><mi>N</mi></mrow><mi mathvariant="normal">c</mi></msub><mo stretchy="false">)</mo></mrow></math> gauge symmetry and thus closely resemble Standard-Model fermions. Unbroken chiral symmetry in the quantum-gravity regime is a necessary prerequisite to recover the Standard Model from a joint gravity-matter theory; if chiral symmetry is broken by quantum gravity, fermions cannot generically be much lighter than the Planck mass, and the theory is ruled out. To answer this, we work in a Fierz-complete basis of four-fermion interactions and explore whether they are driven to criticality. We discover that the interplay of quantum gravity with the non-Abelian gauge theory results in chiral symmetry breaking, because gravitational and gauge field fluctuations act together to produce bound states. Chiral symmetry breaking is triggered by four-fermion channels that first appear when non-Abelian charges are introduced and that become critical if the non-Abelian symmetry is gauged. Extrapolating our result to the Standard Model fermions, we conjecture that the non-Abelian gauge coupling, Abelian gauge coupling and Newton coupling are all bounded from above at trans-Planckian scales, if Standard Model fermions are to remain much lighter than the Planck mass. In contrast, fermions that are charged under a global non-Abelian group can remain light for arbitrarily large values of the Newton coupling. We find that different chiral symmetries are emergent at low energies, depending on the strength of the gravitational coupling. This is an example of fixed points with different degrees of enhanced global symmetry trading stability in fixed-point collisions driven by gravitational fluctuations.

Brazil

Denmark

Gustavo P. de Brito

Astrid Eichhorn

Faroe Islands

Shouryya Ray

Why the quark mass is not the Planck mass

A technique to build perturbative series for the spectator field’s correlation functions in de Sitter space through the Fokker-Planck equation is proposed. We derive from the first-order differential equation the iterative integral relation for equal- and multi-time correlation functions. With an appropriate integration, the obtained two-point and four-point correlation functions are in agreement with quantum field theory’s ones.

Alexander Kamenshchik

Polina Petriakova

From the Fokker-Planck equation to perturbative QFT’s results in de Sitter space

The Quantum Focusing Conjecture (QFC) lies at the foundation of holography and semiclassical gravity. The QFC implies the Bousso bound and the Quantum Null Energy Condition (QNEC). The QFC also ensures the consistency of the quantum extremal surface prescription and bulk reconstruction in AdS/CFT.

Raphael Bousso

Elisa Tabor

Discrete Max-Focusing

China

Li-Yang Chen

Hongwei Yu

Puxun Wu

Erratum to: A model of inflation consistent with Planck 2018 and BICEP/Keck data

We propose a dark matter (DM) model with a complex scalar charged under a hidden gauge symmetry denoted as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi mathvariant="normal">D</mi></msub></math>. The scalar field is the DM candidate while the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi mathvariant="normal">D</mi></msub></math> gauge field <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>A</mi><mo>′</mo></msup></math> plays the role of a mediator, which connects the dark sector to the standard model (SM) sector via a tiny kinetic mixing. We find that both the secluded and catalyzed-annihilation scenarios can be realized in this model. The phenomenology of DM, including relic density, indirect detection (Fermi-LAT), and cosmic microwave background (CMB; Planck) constraints, is discussed. We also extend our discussion to DM with other spins, including the Dirac fermion and vector boson. Our analysis is carried out in two models denoted as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi mathvariant="normal">D</mi></msub><mo>×</mo><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi mathvariant="normal">Y</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi mathvariant="normal">D</mi></msub><mo>×</mo><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mrow><msub><mi>L</mi><mi>μ</mi></msub><mo>−</mo><msub><mi>L</mi><mi>τ</mi></msub></mrow></msub></math>, with the former corresponding to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>A</mi><mo>′</mo></msup></math> kinetically mixing with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi mathvariant="normal">Y</mi></msub></math> gauge field <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> and the latter corresponding to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>A</mi><mo>′</mo></msup></math> mixing with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mrow><msub><mi>L</mi><mi>μ</mi></msub><mo>−</mo><msub><mi>L</mi><mi>τ</mi></msub></mrow></msub></math> gauge field <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Z</mi><mo>′</mo></msup></math>. We find that in previous studies of catalyzed-annihilation scenarios, the indirect detection limits were overly restrictive because they only considered the simplified <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>DM</mi><mo stretchy="false">→</mo><mn>2</mn><mi>SM</mi></math> annihilation channel. In contrast, by performing a complete calculation of the gamma-ray and CMB constraints from the process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>DM</mi><mo stretchy="false">→</mo><mn>2</mn><msup><mi>A</mi><mo>′</mo></msup><mo stretchy="false">→</mo><mn>4</mn><mi>SM</mi></math> in the models we consider, we observe weaker constraints in both the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi mathvariant="normal">D</mi></msub><mo>×</mo><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi mathvariant="normal">Y</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi mathvariant="normal">D</mi></msub><mo>×</mo><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mrow><msub><mi>L</mi><mi>μ</mi></msub><mo>−</mo><msub><mi>L</mi><mi>τ</mi></msub></mrow></msub></math> models, with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi mathvariant="normal">D</mi></msub><mo>×</mo><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mrow><msub><mi>L</mi><mi>μ</mi></msub><mo>−</mo><msub><mi>L</mi><mi>τ</mi></msub></mrow></msub></math> model being subject to the weakest constraints overall since it involves fewer hadronic decay processes.

Yu-Hang Su

Chengfeng Cai

Hong-Hao Zhang

Constraining secluded and catalyzed-annihilation dark matter models with Fermi-LAT and Planck data

Modified dispersion relations (MDRs) and noncommutative geometries are phenomenological models of Planck-scale corrections to relativistic kinematics, motivated by several approaches to quantum gravity. High-energy astrophysical observations, while commonly used to test such effects, are limited by significant systematic uncertainties. In contrast, low-energy, nonrelativistic experiments provide greater control, with precision serving as an amplifier for Planck-suppressed corrections. We derive corrections to Pauli’s equation for nonrelativistic spin-1/2 particles in a magnetic field, incorporating general MDRs and noncommutative geometries. Applying our framework to $$\kappa $$ -Poincaré symmetries and minimal-length quantum mechanics, we identify Planck-scale corrections accessible in the nonrelativistic regime. Using the electron’s anomalous magnetic moment, we constrain model parameters, pushing the $$\kappa $$ -Poincaré scale in the bi-crossproduct representation beyond $$10^{10} ~\text {GeV}.$$ These results highlight the complementarity of low-energy precision tests and astrophysical observations in probing quantum gravity phenomenology.