The Hubble tension has profoundly shaped modern cosmological research. This study explores its impact on the early-universe physics in the modified emergent dark energy (MEDE) and $$\Lambda $$ CDM model using Planck PR4, BK18, DESI2024/2025, and supernova samples (Pan+, Union3). First, Hubble constant negligibly affects the tensor-to-scalar ratio ( $$r < 0.031$$ at 95%C.L.). Inclusion of DESI2025 achieves a 46% uncertainty reduction in key parameters. For CMB power spectra, DESI systematically amplifies TT/BB spectral discrepancies. Second, electron ionization fractions $$X_e(z)$$ display pronounced deviations from the $$\Lambda $$ CDM model at $$z=9.17$$ , suggesting a connection between Hubble tension and reionization history. This finding resonates with JWST measurements on high-redshift galaxy evolution. Future observations, such as 21-cm surveys, are highly anticipated to resolve these tensions by probing early-universe evolution and dark energy interactions.

China

Ming-Jian Zhang

Maoyou Yang

Junmei Wang

Testing influence of Hubble tension on the early Universe

We introduce the Higgs mechanism for the self-dual spin connection (also known as the Ashtekar connection), using the Plebański formulation of gravity. We develop our formalism within the framework of the chiral action and derive the equations of motion of the theory. One particular test model is explored: since anisotropy is an intrinsic property of the theory, a modified version of the spatially flat Bianchi I model with two different scale factors is considered. We apply our formalism and derive the Friedmann equations which regulate the scale factors and the Higgs field. We also present a Proca-like term for the connection, which when reduced to minisuperspace with a positive $$\Lambda $$ yields a De Sitter universe with an effective cosmological constant that depends on the mass of the gauge fields. We finally investigate the effect of these mass terms on gravitational waves and find that the wave equation remains unchanged relatively to GR; however the Weyl tensor is scaled by a constant which depends on the mass of the connection components.

United Kingdom

Bruno Alexandre

Higgs mechanism for the Ashtekar self-dual connection

The manifest disparity in Hawking radiation temperatures between black hole and cosmological horizons in de Sitter (dS) spacetime reveals a non-equilibrium thermal configuration, inherently violating thermodynamic stability criteria. This asymmetry poses significant challenges to the systematic analysis of dS thermodynamics. In this study, we construct a thermodynamic framework for dS spacetime under the condition that the system’s thermodynamic quantities adhere to the first law of thermodynamics, while enforcing thermal equilibrium between horizons through radiation temperature-equivalent conditions. Our ansatz postulates that spacetime entropy constitutes both horizon entropy contributions with a supplementary correction term. Through variational analysis constrained by equilibrium thermodynamics, we derive and solve thermodynamic constraints to obtain corrected entropy relations that explicitly resolve the two-horizon entropy puzzle for $\textit{n}$-dimensional charged dilaton-dS black holes. Utilizing these corrected entropy relations, we renormalize associated thermodynamic quantities, thereby establishing self-consistent extended thermodynamics. Numerical solutions of the Gibbs criteria reveal parameter-dependent critical points, where heat capacity is diverging signal possible second-order phase transitions. The system manifests phase transition phenomena, structurally homologous to liquid–gas transition in conventional thermodynamic systems. We proved that the system satisfies the conditions for equilibrium stability, allowing equilibrium phase transitions to occur near critical points.

Hui-Hua Zhao

Yun-Zhi Du

Yu-Bo Ma

Entropy correction and phase transition of $\textit{n}$-dimensional charged dilaton dS black holes

Direct detection experiments have started to explore dark matter scattering off electrons and nucleons through light mediators. Mediators with sub-keV masses are efficiently produced in the Sun and can be absorbed in the same detectors that probe dark matter scattering. We investigate the interplay of dark matter scattering and mediator absorption for two models with a dark photon as mediator. For Dirac dark matter, we find that scattering and absorption can be simultaneously observed at direct detection experiments in the near future. For atomic dark matter, we predict additional signals due to scattering of both dark atoms and constituents from ionized dark atoms. In both models, we determine the parameter space that respects bounds from cosmology and astrophysics, where the strongest constraints come from dark matter self-interactions. In this way, we identify viable targets for dark matter with light mediators at upcoming direct detection experiments. Distinguishing between the various signals, for instance by measuring energy distributions, will be crucial to reveal the underlying model in case of a discovery.

Netherlands

Pieter Braat

Anh Phan

Marieke Postma

Susanne Westhoff

Scattering meets absorption in dark matter detection

We construct new families of supersymmetric AdS solutions in both massive and massless Type IIA supergravity via deformations to known backgrounds preserving $$ \mathcal{N} $$ = (4, 0) and $$ \mathcal{N} $$ = (6, 0) supersymmetry. These deformations are performed along internal isometries and lead to backgrounds with fully preserved or reduced supersymmetry. Using the formalism of $\textit{G}$-structures, we systematically characterise the resulting geometries and track the evolution of their supersymmetric properties under the deformation. In particular, we identify transitions among SU(3), SU(2), and identity structures, and demonstrate the preservation of Killing spinors through explicit spinor bilinear constructions. Additionally, we investigate D-brane embeddings in the deformed geometries, uncovering stable and supersymmetric configurations supported by the new backgrounds. Our results offer new insights into the classification of AdS flux vacua and provide a concrete framework for understanding their potential holographic duals.

Belgium

Anayeli Ramírez

Czechia

Salomón Zacarías

On deformations of AdS

We present an analytic reconstruction of one-loop amplitudes for the process $$ 0\to \overline{q} qt\overline{t}H $$ . Our calculation is a novel use of analytic reconstruction, retaining explicit covariance in the massive spin states through the massive spinor-helicity formalism. The analytic reconstruction relies on embedding the massive five-point kinematics in a fully massless eight-point phase space while still building a minimal ansatz directly in the five-point phase space. In order to obtain compact analytic expressions it is necessary to identify suitable partial fraction decompositions and extract common numerator factors, which we achieve through careful inspection of limits in which pairs of denominators vanish. We find that the resulting amplitudes are more numerically efficient than ones computed using automatic methods but that the gains are not as significant as in the massless case, at least at present. The method opens the door to applications at two-loop order, where numerical efficiency and improvements in the reconstruction methodology are more crucial, especially with regards to the number of free parameters in the ansatz.

United States

John Campbell

Giuseppe Laurentis

R. Ellis

Analytic reconstruction with massive particles: one-loop amplitudes for $$ 0\to \overline{q} qt\overline{t}H $$

This study investigates the decay modes of the $\textit{B}$ meson, focusing on semileptonic and nonleptonic decay into S and P wave charmonia. The primary objective is to extract the shape parameter of the $\textit{B}$ meson distribution amplitude through a data-driven approach, utilizing the lattice results on $\textit{B}$ → $\textit{η}$ , $\textit{J}$/$\textit{ψ}$ semileptonic form factors and yielding an estimate of $\textit{ω}$ = 0.998(34) GeV for the same. We use the form factors derived from the modified perturbative QCD framework in the analysis. This result and various other inputs on the radiative decays of the P wave charmonia enable us to estimate the $\textit{q}$ shapes of the $\textit{B}$ → $\textit{χ}$ , $\textit{χ}$ and $\textit{h}$ form factors using pole expansion parametrization. Using these results, we have obtained predictions of LFUV observables $\textit{R}$($\textit{χ}$ ) = 0.169(11), $\textit{R}$($\textit{χ}$ ) = 0.126(2) and $\textit{R}$($\textit{h}$ ) = 0.113(3). Finally, we have presented predictions for branching ratios of some nonleptonic decay modes of the $\textit{B}$ meson into S and P wave charmonia in the same modified perturbative QCD framework.

India

Utsab Dey

Soumitra Nandi

Correlated study on some $\textit{B}$

We present an analytic calculation of the integrated double-emission eikonal function of a massive and a massless emitter whose momenta are at an arbitrary angle to each other. This quantity provides one of the required ingredients for extending the nested soft-collinear subtraction scheme to processes with massive final-state particles. To calculate it, we use the standard methodology involving reverse unitarity and its extension to cases with Heaviside functions, integration-by-parts technology and reduction to master integrals, and differential equations. In addition, we also describe a semi-numerical method based on the subtraction of infra-red and collinear singularities from the eikonal function, allowing us to extract divergences of the integrated eikonal function analytically, and to derive a simple integral representation for the finite remainder.

Germany

Dennis Horstmann

Kirill Melnikov

Ming-Ming Long

Andrey Pikelner

Integral of the double-emission eikonal function for a massive and a massless emitter at an arbitrary angle

Conformal higher-spin gravity is the log-divergent part of the effective action of the scalar field coupled to background fields via higher-spin currents, as was defined by Segal and Tseytlin, which can be worked out over the flat space background. We revisit the problem of the scalar field in a higher-spin background and propose a manifestly covariant version thereof. The construction utilizes the Fedosov quantization of the cotangent bundle and the action is written with the help of the trace on a curved phase space that is provided by the Feigin-Felder-Shoikhet cocycle. The same construction allows one to formulate quantum mechanics on a curved space, the phase space being the cotangent bundle.

Thomas Basile

Shailesh Dhasmana

Evgeny Skvortsov

Scalar field on a higher-spin background via Fedosov quantization

We present analytic results for electroweak precision observables (EWPO) at next-to-leading order (NLO) in dimension-six SMEFT, with no assumptions on the flavour structure of SMEFT Wilson coefficients. The results are given in five different electroweak input schemes, thus offering a simple means, along with scale variations, of estimating theory uncertainties related to higher-order terms in the SMEFT expansion. Our results will be useful to assess the constraining power of existing and future lepton colliders for new physics scenarios.

Anke Biekötter

Benjamin Pecjak

Analytic results for electroweak precision observables at NLO in SMEFT