We propose a simple, renormalizable scenario in which all of dark energy arises from a one-loop Coleman–Weinberg potential induced by a scalar field Yukawa-coupled exclusively to Standard-Model neutrinos. Classically, $$V_{\min }=0$$ , but neutrino loops lift the vacuum by $$\rho _{\text {DE}}=\frac{y^{2}m_{\nu }^{6}}{512\pi ^{4}m_{\phi }^{2}}$$ , matching the observed dark energy scale for $$y\approx 0.28m_{\phi }/$$ eV and $$m_{\nu }\sim 0.1\,$$ eV. We detail cosmological tracking, demonstrate stability against neutrino clumping, and show that rapid scalar oscillations leave no detectable imprint on current neutrino-oscillation experiments—though they provide a clear target for future high-precision probes. Compared to other mass varying neutrino models, our framework employs only a renormalizable quadratic potential, avoids unnatural hierarchies, and makes concrete, testable predictions.

Georgia

Z. Kepuladze

Quantum dark energy from neutrino loops: model, stability and oscillation imprints

We develop a unified dynamical systems framework for spatially flat FLRW cosmology in $\textit{f}$($\textit{Q}$) gravity, covering all three connection branches using a single set of Hubble-normalised variables without fixing the function $\textit{f}$($\textit{Q}$) a priori. This model-independent and connection-agnostic approach enables direct comparison across connection choices and uncovers structural features of the cosmological dynamics not visible in connection-specific formulations. While the existing works narrowly focus only on fixed point analysis, in our work we put special efforts to identify the invariant submanifolds, model-independent trajectories and physically viable regions of phase space across connections. For a broad class of viable $\textit{f}$($\textit{Q}$) models, we establish the generic existence of de Sitter attractors and matter-dominated fixed points in the two branches of connection, offering a robust route to late-time acceleration without fine-tuning. We further identify an invariant submanifold that yields $$\Lambda $$ CDM-like background evolution despite underlying dynamics distinct from General Relativity, providing a geometric origin for cosmic acceleration distinguishable only at the perturbation level. We also derive a first integral on this submanifold, allowing analytic reconstruction of the dynamical connection and uncovering hidden conservation laws. Another key feature we found is that while trivial connections exhibit strong parameter dependence, the nontrivial branches often feature parameter-independent behaviours. We also study the variation of the effective gravitational coupling, $$k_{\text {eff}}$$ , across branches and show how this can be constrained using astrophysical observations, which bridges theoretical viability with observational consistency in a novel way. Applying our framework to the illustrative model $$f(Q)=\alpha Q + \beta (-Q)^n$$ , we find late-time acceleration and $$\Lambda $$ CDM-like behaviour without vacuum energy. Finally, we propose a general route for extending dynamical systems analysis to broader classes of $\textit{f}$($\textit{Q}$) models using the $$m_i$$ -hierarchy method. This framework enables closure for models previously inaccessible to standard approaches and offers a diagnostic tool for identifying structurally viable cosmologies within modified gravity theories.

India

Jibitesh Dutta

Wompherdeiki Khyllep

Thailand

South Africa

Saikat Chakraborty

China

Daniele Gregoris

Khamphee Karwan

A unified dynamical systems framework for cosmology in $\textit{f}$($\textit{Q}$) gravity: generic features across the connection branches

We investigate the Domain-Wall Standard Model (DWSM), a five-dimensional framework in which all Standard Model (SM) particles are localized on a domain wall embedded in a non-compact extra spatial dimension. A distinctive feature of this setup is the emergence of a Nambu–Goldstone (NG) boson, arising from the spontaneous breaking of translational invariance in the extra dimension due to the localization of SM chiral fermions. This NG boson couples via Yukawa interactions to SM fermions and their Kaluza–Klein (KK) excitations. We study the phenomenology of this NG boson and derive constraints from astrophysical processes (supernova cooling), Big Bang Nucleosynthesis (BBN), and collider searches for KK-mode fermions at the Large Hadron Collider (LHC). The strongest limits arise from LHC data: we reinterpret existing mass bounds on squarks and sleptons in simplified supersymmetric models (assuming a massless lightest neutralino), as well as limits on exotic hadrons containing long-lived squarks or long-lived charged sleptons in the regime of extremely small Yukawa couplings. From this analysis, we obtain a conservative lower bound of 1 TeV on the masses of KK-mode quarks and charged leptons. Finally, we discuss the prospects for producing KK-mode fermions at future high-energy lepton colliders and outline strategies to distinguish their signatures from those of sfermions.

United States

Puja Das

Nobuchika Okada

Digesh Raut

Desmond Villalba

Nambu–Goldstone boson phenomenology in domain-wall standard model

To date, wormholes have not been observed. Dynamic wormholes are difficult to detect due to their transient existence or extremely low spacetime curvature contrast, while static wormholes rely on “exotic matter” that violates the Null Energy Condition and lack direct theoretical support. This study explores the mechanism of dynamic wormhole formation via gravitational collapse of Bose–Einstein Condensate (BEC) dark matter in generalized Vaidya spacetime. Under specific conditions, the gravitational collapse of BEC dark matter interacts with gravitational fields to trigger abrupt changes in spacetime topology. This process depends on special parameters that are more likely to be satisfied in extreme environments. During the collapse, the condensate properties of BEC influence the evolution of spacetime curvature, and its intrinsic oscillatory behavior may facilitate the formation of dynamic wormholes. The research deduces function constraints that satisfy various energy conditions, constructs a dynamic wormhole form adapted to generalized Vaidya spacetime, and derives the Hawking radiation expression and mass function constraints by combining Lorentz-breaking quantum gravity theory. This mechanism confirms the feasibility of dynamic wormhole formation, provides a new perspective for understanding the behavior of dark matter under extreme gravity and the evolution of spacetime topology, and advances wormhole research toward the analysis of dynamic formation processes.

Junjie Wei

Discussion on the feasibility of dynamic wormhole formation based on the gravitational collapse of Bose–Einstein condensed dark matter on generalized Vaidya space-time

We propose a unified model of dark energy and inflation through the Markov–Mukhanov modification of the Einstein–Hilbert action, where the matter sector is coupled to gravity via a scalar coupling function depending only on the energy density of the matter content. We assume that the coupling function encodes the UV corrections to the standard model of cosmology and we determine the form of the coupling that allows for the dark energy component to be dynamical and act as the inflaton field in the early universe. Interestingly we show that our model, in order to account for inflation, prefers a dark energy equation of state with $\textit{w}$ close but not equal to $$-1$$ in agreement with the latest DESI data.

Kazakhstan

Hrishikesh Chakrabarty

Daniele Malafarina

A unified model of dark energy and inflation from the Markov–Mukhanov action

We present a PyTorch-based framework for forward folded reactor neutrino spectrum fitting that accelerates the two main bottlenecks: IBD mapping and detector response, using (i) result caching, (ii) banded sparse matrices, and (iii) blocked construction of the response. On an Intel Xeon Gold 6338 CPU, these techniques reduce per-fit walltime by $$\approx 7\times $$ (median over 5 runs) relative to a dense, unoptimized implementation, with $$<10^{-6}$$ relative spectral error versus a double-precision baseline. The framework has been applied to reactor-neutrino oscillation analyses and is reusable in other neutrino experiments that rely on forward-folded energy spectra, enabling practical Feldman–Cousins coverage studies and large parameter scans at substantially lower computational cost.

Jingqin Xue

Han Zhang

Hongfang Shen

Guangbao Sun

Dian Li

Liangqianjin Fan

Haifeng Yao

Liang Zhan

Xiang Zhou

Xuefeng Ding

High-performance statistical methods for reactor neutrino oscillations

In this paper, we study Proca stars in asymptotically anti-de Sitter (AdS) Ellis wormholes. This study distinguishes itself from the analysis of the Proca stars in asymptotically flat spacetimes. In the AdS Ellis wormhole background, the mass of the wormhole solutions vanishes. Consequently, we employ numerical techniques to investigate in detail the impact of the cosmological constant on both the matter field and the wormhole geometry, while categorizing the solutions in accordance with the symmetries of the Proca field. The results show that when the cosmological constant decreases, not only does the characteristic spiral behavior of the Proca star solutions, namely the charge-frequency relation $\textit{Q}$– $$\omega ,$$ gradually disappear, but the throat or both sides of the wormhole may also develop a “horizon”, presenting a “black bounce” characteristic.

Gen Li

Chen-Hao Hao

Xin Su

Yong-Qiang Wang

Proca stars in AdS Ellis wormholes

In this paper, we investigate a digitised SU(2) lattice gauge theory in the Hamiltonian formalism. We use partitionings to digitise the gauge degrees of freedom and show how to define a penalty term based on finite element methods to project onto physical states of the system. Moreover, we show for a single plaquette system that in this framework the limit $$g\rightarrow 0$$ can be approached at constant cost.

Germany

Timo Jakobs

Marco Garofalo

United Kingdom

Tobias Hartung

Cyprus

Karl Jansen

Johann Ostmeyer

Switzerland

Simone Romiti

Carsten Urbach

Dynamics in hamiltonian lattice gauge theory: approaching the continuum limit with partitionings of SU(2)

We explore the possibility of realizing a non-singular bounce in the early universe within the framework of modified gravity with spacetime torsion. In Einstein Cartan theory, torsion is embedded in the spacetime by adding an antisymmetric part in affine connection. We consider generalized version of the framework as $$f(\bar{R})$$ , $$\bar{R}$$ being the scalar of the modified curvature tensor. $$f(\bar{R})$$ gravity is recast in Einstein frame as non-minimally coupled scalar tensor theory where the scalar field gets coupled with a rank 2 antisymmetric torsion field through derivative couplings. We investigate whether the introduction of three additional torsion-dependent terms in Einstein frame help to realize a bounce. We first explore this cosmological system in the background of a homogeneous and isotropic FRW spacetime but inclusion of the torsion terms are insufficient to produce a bounce in this symmetric setting. Motivated by this limitation, we relax the symmetry and generalize the background to include inhomogeneity and anisotropy. In this setup, the dynamics is modified in such a way that a bouncing solution is possible without invoking phantom fields or energy condition violations. We have found the exact solutions of all the fields and reconstructed the modified gravity form. We have addressed the behaviour of the fields under perturbation and investigated the stability of the solutions. Constraints on the model parameters have also been derived based on cosmological observations.

Sonej Alam

Somasri Sen

Soumitra Sengupta

Bouncing cosmologies in modified gravity with spacetime torsion

We perform an analysis of the scalar sector of 3 Higgs Doublet Models with softly broken $$\Delta (54)$$ and $$\Sigma (36)$$ symmetries. We consider the various vacuum expectation value alignments and consider, for each, softly broken terms that deviate the alignment. We check the evolution of the minima, present analytical and numerical results for the lifting of the degeneracies of the physical eigenstates, and describe the decays of the states considering any residual symmetries.

Portugal

Gonçalo Barreto

Ivo Medeiros Varzielas

3HDM with softly broken $$\Delta (54)$$ and $$\Sigma (36)$$