We investigate the thermodynamic behavior of a spherically symmetric Anti-de Sitter black hole in Mod(A)Max electrodynamics surrounded by a cloud of strings. Within the extended phase-space framework, we treat the cosmological constant as a pressure and interpret the black-hole mass as enthalpy, which enables a unified discussion of local stability, global phase structure, and Joule–Thomson expansion. We analyze the Hawking temperature, Gibbs free energy, and heat capacity, and show how the string-cloud parameter, the Mod(A)Max deformation, and the electric charge reshape the physical domain, the stability windows, and the small/large black-hole transition pattern. We further characterize the critical behavior and demonstrate that a van der Waals–like phase structure arises only in the physical sector, while the alternate branch does not admit a genuine critical point. For the Joule-Thomson process, we determine the inversion curve and the corresponding isenthalpic trajectories, highlighting how the model parameters control the cooling/heating regimes and can generate terminating isenthalpic behavior at sufficiently large charge. Finally, we examine the sparsity of Hawking radiation and discuss how the underlying parameters influence the temporal discreteness of the emitted flux, particularly near extremality and in the large-radius AdS regime.

India

Faizuddin Ahmed

Jordan

Ahmad Al-Badawi

Brazil

Edilberto O. Silva

Thermal analysis, Joule-Thomson expansion and Hawking sparsity of Mod(A)Max-AdS black hole immersed in a cloud of strings

We investigate the impact of one-loop radiative corrections in a nonsupersymmetric model of hybrid inflation with a chaotic (polynomial-like) potential, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>V</mi><mo stretchy="false">(</mo><mi>ϕ</mi><mo stretchy="false">)</mo><mo>=</mo><msub><mrow><mi>V</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>+</mo><msub><mrow><mi>λ</mi></mrow><mrow><mi>p</mi></mrow></msub><msup><mrow><mi>ϕ</mi></mrow><mrow><mi>p</mi></mrow></msup></mrow></math>, in the light of the latest constraints from Planck and Atacama Cosmology Telescope (ACT) observations. Here, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>V</mi><mn>0</mn></msub></math> denotes the energy scale of inflation, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>λ</mi><mi>p</mi></msub></math> is a coupling associated with the polynomial term of power <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi></math>. These corrections can naturally arise from couplings of the inflaton to other matter fields, which also facilitate the reheating process. At the tree level, the predictions of such models for the scalar spectral index <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>n</mi><mi>s</mi></msub></math> and the tensor-to-scalar ratio <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>r</mi></math> typically lie outside the current observational bounds. However, incorporating one-loop radiative corrections modifies the potential to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>V</mi><mo stretchy="false">(</mo><mi>ϕ</mi><mo stretchy="false">)</mo><mo>=</mo><msub><mrow><mi>V</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>+</mo><msub><mrow><mi>λ</mi></mrow><mrow><mi>p</mi></mrow></msub><msup><mrow><mi>ϕ</mi></mrow><mrow><mi>p</mi></mrow></msup><mo>+</mo><mi>A</mi><msup><mrow><mi>ϕ</mi></mrow><mrow><mn>4</mn></mrow></msup><mi>ln</mi><mo stretchy="false">(</mo><mi>ϕ</mi><mo>/</mo><mi>μ</mi><mo stretchy="false">)</mo></mrow></math>, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>A</mi></math> characterizes the strength of the inflaton’s coupling to other fields, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>μ</mi></math> is an appropriate renormalization scale. This radiatively corrected potential can reconcile the model with the combined <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>Planck</mi><mo>+</mo><mi>ACT</mi></mrow></math> data over a suitable range of parameter space explored in this work. In particular, radiative corrections from fermionic loops (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>A</mi><mo>&lt;</mo><mn>0</mn></math>) suppress the tensor-to-scalar ratio <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>r</mi></math>, while simultaneously yielding a red-tilted spectrum with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>n</mi><mi>s</mi></msub><mo>&lt;</mo><mn>1</mn></math>, even for sub-Planckian field excursions. This brings the prediction in line with current observations, while still allowing for potentially detectable signatures of primordial gravitational waves. Furthermore, the inflaton’s couplings enable successful reheating and naturally accommodate nonthermal leptogenesis, providing a unified framework for inflation and baryogenesis.

Waqas Ahmed

Saleh O. Allehabi

Mansoor Ur Rehman

Revisiting polynomial hybrid inflation: Planck and ACT compatibility via radiative corrections

We investigate the quasinormal modes (QNMs) of Planck stars within the framework of scale-dependent gravity (SDG). In our setup, the running parameter $$\alpha $$ is fixed to a negative value by matching the effective Newtonian potential to the one-loop EFT result. As a consequence, the associated running Newton coupling does not realise the ultraviolet fixed point of asymptotically safe gravity, and the geometry should be interpreted as an SDG-inspired effective metric rather than a realisation of asymptotically safe gravity itself. We focus on the resulting renormalisation-group-improved Schwarzschild metric, which naturally yields a finite-size Planck-density core. Building on this background, we compute the QNM spectrum for scalar, electromagnetic, and gravitational perturbations using the Spectral Method (SM). This approach, known for its superior accuracy over high-order WKB schemes, enables the detection of fundamental modes, large families of overtones, and purely imaginary overdamped modes that are entirely missed in previous analysis. Our results reveal a robust $\textit{Martini glass}$ morphology of the oscillatory spectrum across perturbation sectors, nearly equally spaced overdamped modes with characteristic anomalous gaps, and the emergence, in the gravitational sector, of isolated overdamped modes separated from the main sequence by exceptionally large frequency intervals. These features, resolved here for the first time in the Planck-star context, underscore the importance of high-precision spectral techniques in probing subtle signatures of quantum-gravity-inspired black hole models.

United Arab Emirates

Davide Batic

Denys Dutykh

Italy

Canada

Fabio Scardigli

Spectral analysis of quasinormal modes of Planck stars

We investigate the propagation of a massless scalar field in the Gödel universe and demonstrate that the rotating spacetime functions as an intrinsically optically active medium, characterized by a refractive index that depends on both position and frequency. Starting from the covariant Klein-Gordon equation, we derive a generalized Helmholtz-type radial equation in which the effective refractive index <italic>n</italic> <inf>&#8728;</inf>( <italic>r, &#969;</italic>) explicitly depends on the radial coordinate <italic>r</italic> and frequency <italic>&#969;</italic>. Consequently, the G&#246;del geometry manifests as a rotation-induced optical medium: scalar modes are confined within a finite radial domain bounded by turning points where <math altimg='si19.svg'><mrow><msubsup><mi>n</mi><mrow><mo>&#8728;</mo></mrow><mn>2</mn></msubsup><mrow><mo>(</mo><mi>r</mi><mo>,</mo><mi>&#969;</mi><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><mn>0</mn></mrow></math>. Depending on the rotation rate &#937;, the frequency <italic>&#969;</italic>, and the azimuthal quantum number <italic>m</italic>, the medium supports either propagating <math altimg='si20.svg'><mrow><mo>(</mo><msubsup><mi>n</mi><mrow><mo>&#8728;</mo></mrow><mn>2</mn></msubsup><mo linebreak='goodbreak'>&gt;</mo><mn>0</mn><mo>)</mo></mrow></math> or evanescent <math altimg='si21.svg'><mrow><mo>(</mo><msubsup><mi>n</mi><mrow><mo>&#8728;</mo></mrow><mn>2</mn></msubsup><mo linebreak='goodbreak'>&lt;</mo><mn>0</mn><mo>)</mo></mrow></math> behavior. Near the rotational axis, a centrifugal singularity emerges, producing strongly evanescent regions for | <italic>m</italic>|&#8239;&gt;&#8239;1/2, whereas for <math altimg='si22.svg'><mrow><mi>m</mi><mo linebreak='goodbreak'>=</mo><mn>0</mn></mrow></math>, propagation persists near the axis but confinement still occurs due to the evanescent asymptotics at large <italic>r</italic>. Asymptotically, <math altimg='si23.svg'><mrow><msubsup><mi>n</mi><mrow><mo>&#8728;</mo></mrow><mn>2</mn></msubsup><mrow><mo>(</mo><mi>r</mi><mspace width='-0.16em' /><mo>&#8594;</mo><mspace width='-0.16em' /><mi>&#8734;</mi><mo>,</mo><mi>&#969;</mi><mo>)</mo></mrow><mo>&#8771;</mo><mo>&#8722;</mo><mn>3</mn><mo linebreak='goodbreak'>&#8722;</mo><mfrac><msup><mstyle mathvariant='normal'><mi>&#937;</mi></mstyle><mn>2</mn></msup><mrow><mn>4</mn><msup><mi>&#969;</mi><mn>2</mn></msup></mrow></mfrac></mrow></math>, rendering all modes evanescent. Planck-scale corrections are incorporated within the framework of rainbow gravity, employing energy-dependent functions <italic>f</italic>(&#1013;) and <italic>g</italic>(&#1013;), where <math altimg='si24.svg'><mrow><mi>&#1013;</mi><mo linebreak='goodbreak'>=</mo><mi>&#969;</mi><mo linebreak='goodbreak'>/</mo><msub><mi>&#969;</mi><mi>p</mi></msub></mrow></math>. We consider (i) loop-quantum-gravity-inspired functions <math altimg='si25.svg'><mrow><mi>f</mi><mrow><mo>(</mo><mi>&#1013;</mi><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><mn>1</mn><mo>,</mo><mspace width='0.28em' /><mi>g</mi><mrow><mo>(</mo><mi>&#1013;</mi><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><msqrt><mrow><mn>1</mn><mo linebreak='badbreak'>&#8722;</mo><mi>&#951;</mi><mi>&#1013;</mi></mrow></msqrt></mrow></math> and (ii) doubly special relativity-inspired functions <math altimg='si26.svg'><mrow><mi>f</mi><mo>(</mo><mi>&#1013;</mi><mo>)</mo><mo>=</mo><mn>1</mn><mo linebreak='goodbreak'>/</mo><mo>(</mo><mn>1</mn><mo linebreak='goodbreak'>&#8722;</mo><mi>&#951;</mi><mi>&#1013;</mi><mo>)</mo><mo>,</mo><mspace width='0.28em' /><mi>g</mi><mo>(</mo><mi>&#1013;</mi><mo>)</mo><mo>=</mo><mn>1</mn></mrow></math>, which induce the frequency deformation <math altimg='si27.svg'><mrow><mi>&#969;</mi><mspace width='-0.16em' /><mo>&#8594;</mo><mspace width='-0.16em' /><mover accent='true'><mi>&#969;</mi><mo>&#732;</mo></mover><mo linebreak='goodbreak'>=</mo><mi>&#969;</mi><mspace width='0.16em' /><mi>f</mi><mrow><mo>(</mo><mi>&#1013;</mi><mo>)</mo></mrow><mo linebreak='goodbreak'>/</mo><mi>g</mi><mrow><mo>(</mo><mi>&#1013;</mi><mo>)</mo></mrow></mrow></math> and lead to a modified refractive index <math altimg='si28.svg'><mrow><mover accent='true'><mi>n</mi><mo>&#732;</mo></mover><mrow><mo>(</mo><mi>r</mi><mo>,</mo><mi>&#969;</mi><mo>,</mo><msub><mi>&#969;</mi><mi>p</mi></msub><mo>)</mo></mrow></mrow></math>. First-order corrections ( <italic>&#951;</italic>&#1013;&#8239;&#8810;&#8239;1) yield analytic shifts of the turning points, while exact closed-form expressions allow precise numerical treatment. The resulting rainbow-induced deformations generate frequency-dependent modifications to the propagation thresholds, which become particularly pronounced near the axis ( <italic>r</italic>&#8239;&#8594;&#8239;0) and in near-Planckian regimes. Furthermore, we demonstrate that these results generalize to <italic>z</italic>-polarized electromagnetic wave modes and show the smooth recovery of scalar-like propagation in the G&#246;del universe. Finally, when <math altimg='si16.svg'><mrow><mi>&#951;</mi><mo linebreak='goodbreak'>=</mo><mn>0</mn></mrow></math>, we establish that in the high-frequency limit ( <italic>&#969;</italic>&#8239;&#8594;&#8239;&#8734;), the effective refractive index accurately reproduces the null geodesics of the spacetime.

Türkiye

Omar Mustafa

Abdullah Guvendi

Semra Gurtas Dogan

Optics in the Gödel universe: Effects of global rotation and Planck-scale corrections

Pulsars convert a significant fraction of their total spin-down power into very high-energy electrons, leading to the formation of TeV halos. While these halos are well characterized at TeV energies, it remains unclear whether pulsars also accelerate electrons efficiently at lower energies and how these particles propagate through their surrounding environments. We aim to test whether synchrotron emission from $$\sim 50$$ – $$300 \, \textrm{GeV}$$ electrons around the Geminga pulsar can be detected in the frequency range observed by the Planck satellite. This would help constrain low-energy particle acceleration and diffusion in the vicinity of pulsars. We model the expected synchrotron emission from Geminga’s TeV halo based on various diffusion and injection spectrum scenarios and compare these predictions to publicly available multi-frequency Planck data. We find no conclusive evidence of spatially extended synchrotron emission associated with Geminga in any of Planck’s frequency bands. Our calculations show that even under favorable diffusion and injection conditions, the predicted synchrotron flux lies well below Planck’s measured background levels.

United States

D. Hooper

E. Pinetti

A. Sokolenko

Searching for synchrotron emission from the geminga TeV halo using the planck satellite

The minimal supergravity framework is applied to a construction of new D-type single-field models of inflation in agreement with precision measurements of the cosmic microwave background radiation by Planck Collaboration, BICEP/Keck Collaboration, Atacama Cosmology Telescope and South Pole Telescope. The inflaton potential, the power spectrum of scalar perturbations, the cosmological observables and the reconstruction procedure can be very simple when using the e-folds as the running variable.

China

Yermek Aldabergenov

Japan

Russia

Sergei Ketov

Single-field D-type inflation in the minimal supergravity in light of Planck-ACT-SPT data

In this work, we construct new classes of topological black hole solutions in anti-de Sitter (AdS) spacetime using a novel model of nonlinear electrodynamics called Modification Maxwell (ModMax) and Modification phantom or Modification anti-Maxwell (ModAMax). We then evaluate the thermodynamic quantities and verify the first law of thermodynamics. Our study examines how the parameters of the ModMax and ModAMax fields, as well as the topological constant, affect the black hole solutions, thermodynamic quantities, and local and global thermal stabilities. Furthermore, within the framework of extended phase space thermodynamics, we analyze the Joule–Thomson expansion process and determine the inversion curves. This analysis reveals that the ModMax and ModAMax parameters significantly alter the cooling and heating behavior of these AdS black holes, depending on their topology. Finally, by treating these topological Mod(A)Max AdS black holes as heat engines, we assess their efficiencies, demonstrating that the parameters of nonlinear electrodynamics and horizon topology play crucial roles in enhancing or suppressing the system’s thermodynamic performance.

Iran

B. Panah

Algeria

B. Hamil

Manuel Rodrigues

Topological Mod(A)Max AdS black holes

Maps of cosmic microwave background (CMB) are extracted from multi-frequency observations using a variety of cleaning procedures. However, in regions of strong microwave emission, particularly in the galactic plane from our own galaxy Milky Way and some extended or point sources, the recovered CMB signal is not reliable. Thus, a galactic mask is provided along with the $\textit{cleaned}$ CMB sky for use with that CMB map which excises sky regions that may still be potentially contaminated even after cleaning. So, to avoid bias in our inferences, we impose such a foreground mask. In this paper, we analyze a cleaned CMB map from $\textit{Planck}$ public release 3 to probe for any foreground residuals that may still be present $\textit{outside}$ the galactic mask where the derived CMB sky is considered clean. To that end, we employ a local cross-correlation coefficient statistic where we cross-correlate widely used foreground templates that trace galactic synchrotron, free-free, and thermal dust emission from our galaxy with the cleaned CMB sky. Using simulations, we find that few regions of the derived CMB sky are still contaminated and have to be omitted. Based on this study, we derived a mask that could be used in conjugation with the standard mask to further improve the purpose of galactic masks.

Sanjeet Patel

Pavan Aluri

Pranati Rath

Pramoda Samal

Probing foreground residuals in cleaned CMB temperature maps from $\textit{Planck}$

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.

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

E. Celi

D. Chaize

M. Chala

M. Chapellier

L. Chaplinsky

G. Chemin

R. Chen

J. Colas

L. Couraud

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

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