Recent combined cosmological analyses have reported mild apparent departures from the cosmological-constant equation of state. Such departures are difficult to interpret because BAO, compressed CMB distance priors, and Type Ia supernovae constrain different projections of the expansion history and carry different calibration degeneracies. We perform controlled ensemble null tests using observable-level Gaussian BAO-like, CMB-like, and supernova-like mock datasets generated from a common fiducial flat $$\Lambda $$ CDM cosmology. The aim is to determine whether each constituent single-probe likelihood block can produce an apparent DDE-like marginalized-posterior displacement, or spuriously exclude the fiducial model, through its own degeneracy structure and calibration freedom. The analysis adopts probe-adapted parameterizations for the BAO scale, the CMB physical matter density, and the supernova normalization degeneracy. With explicit convergence diagnostics, percentile-based posterior coverage tests, and realization-level pull statistics, none of the three single-probe analyses spuriously excludes the fiducial input at the 95% level. All completed BAO and SNe chains enter their final ensembles after adaptive extension of the originally rejected runs; for compressed CMB, a mock-data-space audit finds no detectable selection dependence within the sensitivity of the 208-mock ensemble. The compressed CMB-only likelihood nevertheless exhibits stable displaced marginalized medians together with broad late-time posterior intervals, illustrating that posterior location and model exclusion are distinct diagnostics. These results show that a displaced marginalized posterior in a single realization is not, by itself, evidence for dynamical dark energy. Such shifts must be interpreted through mock-ensemble recovery, convergence diagnostics, and the probe-dependent geometry of the likelihood.

South Korea

Seokcheon Lee

Controlled ensemble null tests of dynamical dark energy hints: single-probe recovery of $$\Lambda $$ CDM with BAO, compressed-CMB, and SNe mocks

We propose a relativistic quantum battery model consisting of an accelerated Unruh–DeWitt detector coupled to a massless scalar field in a de Sitter and anti-de Sitter spacetimes. The maximal amount of quantum extractable work, defined as the ergotropy, is used to probe Unruh–Hawking thermality induced by acceleration and spacetime curvature. Using the open quantum system approach, we study the dynamics of the ergotropy with respect to the Kubo–Martin–Schwinger temperature, spacetime boundary conditions, and dimensionality. It has been found that the asymptotic value of quantum work extraction is determined solely by the acceleration and curvature. The steady behavior in the two spacetimes can be unified to witness the Unruh–Hawking thermality which is independent of boundary conditions and dimensionality. From a perspective of time-dependent evolution, we investigate how the ergotropy evolves through different pathways as the battery gradually reaches the same thermal equilibrium state characterized by a certain KMS temperature. In dS spacetime, the evolution at large acceleration exhibits pronounced oscillations and differs from the fast thermal relaxation observed at low acceleration. Varying the boundary condition in AdS can improve the energy storage of the moving battery. When the dimension of AdS is increased, vacuum fluctuations can modestly amplify the ergotropy in the initial stage and facilitate the rapid thermalization. From the perspective of energy transfer, the relativistic quantum battery helps explore the thermal vacuum in curved spacetimes.

Canada

China

Xiang Hao

Tao-Feng Gan

Cheng-Tai Wu

Tian-Xi Ren

Wei-Wei Zhang

Yin-Zhong Wu

Quantum thermodynamics of ergotopy for a relativistic battery as a witness to Unruh–Hawking thermality in curved (A)dS spacetimes

We study the Stodolsky effect utilizing the most general form of neutrino interactions with electrons below the electroweak scale by considering all possible Lorentz invariant operators respecting SU(3) ⨂ U(1) symmetry. We perform our calculation for both Dirac and Majorana neutrinos and find that in the most general setting, only the non-standard neutrino interactions and the tensor interaction terms provide a non-zero contribution, apart from the Standard Model contribution. We investigate the implications for the possible detection of the cosmic neutrino background (C$\textit{ν}$B) by analysing the energy shifts that are characteristic of the Stodolsky effect. We also discuss the implication of considerable asymmetry in the C$\textit{ν}$B on the present scenario.

India

Siddhartha Bandyopadhyay

Ujjal Dey

Stodolsky effect in the framework of generalised neutrino interactions

We perform a comprehensive study of a certain class of discrete symmetries of families of Feynman integrals, defined as affine changes of variables that map different sectors of the family into each other. We show that these transformations are always encoded into permutations of the Feynman parameters that relate the Lee-Pomeransky polynomials of the two sectors, irrespective of the integral representation used to define the Feynman integrals. We then construct an affine map in loop-momentum space that encodes such a permutation. We also show that these symmetries can be naturally embedded into the framework of twisted cohomology theories, and the period and intersection parings are invariant under the symmetry transformations. If we focus on symmetries within a fixed sector, we obtain a group acting on the twisted cohomology group, and we study the decomposition of this action into irreducible representations. One of our main mathematical results is that the character of this representation is proportional to the Euler characteristic of the corresponding fixed-point set. We then study the implications for Feynman integrals, in particular for the intersection matrix in a canonical basis. We also present a formula for the number of master integrals in a given sector in the presence of a non-trivial symmetry group in terms of the Euler characteristics of fixed-point sets. As an application, we obtain the numbers of master integrals for banana integrals with up to four loops for arbitrary configurations of non-zero masses. In order to achieve our results, we had to combine tools from various different areas of mathematics, including graph theory, group theory and algebraic topology.

Germany

Claude Duhr

Sara Maggio

Cathrin Semper

Sven Stawinski

Discrete symmetries of Feynman integrals

We develop a simple framework for implementing a type of path integral “surgery” through a correlated averaging over codimension-one defects/extended operators. This technique is then used to construct replica manifolds by effectively cutting and gluing the path integral without explicitly modifying the underlying manifold. We argue that restricted forms of this averaging may be used to calculate Rényi entanglement entropy corresponding to a wide range of choices of subsystem partitioning. When the entanglement entropy being calculated in this way does not simply correspond to entanglement between subregions, we call the resulting objects from this surgery “generalized replica manifolds”. We show how this framework extends to gauge theories and, in particular, how in non-Abelian gauge theories it establishes a connection between replica calculations of a gauge-invariant notion of entanglement between color degrees of freedom and a quiver gauge theory structure. Finally, we discuss how this framework looks in the context of large-$\textit{N}$ theories and holography, with a bird’s-eye view of potential future directions. This paper focuses on averaging over operators that form a representation of the Heisenberg group; a subsequent paper will focus on how we can extend this framework to more general operator averaging.

United States

Mohamed Radwan

Generalized replica manifolds. Part I. Surgery and averaging

We investigate the critical behavior of the first four cumulants of the net-baryon number near the deconfinement critical point in QCD in the limit of heavy quarks. By connecting baryon-number fluctuations to Polyakov loop susceptibilities, we analyze their mean-field scaling properties at zero and nonzero baryon chemical potentials. In the mean-field approximation we derive critical exponents via the Landau theory and validate them through explicit numerical calculations in an effective Polyakov loop model. Using a Ginzburg-Landau criterion as a diagnostic of beyond-mean-field effects, we estimate the size of the critical region and find that it shrinks with increasing baryon density. By utilizing the exact scaling function in the 3D Ising model, we estimate critical exponents beyond the mean-field approximation.

Poland

Michał Szymański

Pok Man Lo

Krzysztof Redlich

Japan

Chihiro Sasaki

Scaling properties of net-baryon number fluctuations at the deconfinement critical point

We assess the impact of future measurements of dihadron production in semi-inclusive deep-inelastic scattering from the CLAS12 and proposed SoLID experiments at Jefferson Lab, as well as from the ePIC experiment at the future Electron-Ion Collider (EIC), on the transversity parton distribution functions (PDFs) and the corresponding tensor charges of the nucleon. To this end, we generate pseudodata for these experiments for a proton target (CLAS12 and ePIC) and a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>He</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>3</mn></mrow></mmultiscripts></mrow></math> target (SoLID and ePIC), and we include these pseudodata in the JAMDiFF global analysis of existing experimental dihadron data. We find that future data from Jefferson Lab will significantly reduce uncertainties in the transversity PDFs in the region of intermediate-to-large quark momentum fractions <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>x</mi></math>, while the EIC will provide strong constraints across the entire range of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>x</mi></math>, allowing for the first experimental test of the predicted small-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>x</mi></math> behavior of the transversity PDFs. In discussing the reduction of uncertainties in the tensor charges, we also compare the results from the data analyses with those from lattice QCD, highlighting scenarios in which compatibility or tension between the two would arise.

Y. Sawaya

C. Cocuzza

G. Matousek

M. McEneaney

A. Metz

D. Pitonyak

A. Prokudin

N. Sato

A. Vossen

Impact of future dihadron production measurements on the transversity distributions and tensor charges of the nucleon

We directly show that the local ratio of the shear viscosity to the entropy density for Unruh radiation at a finite distance from the horizon is universal and satisfies the relation <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>η</mi><mo>/</mo><mi>s</mi><mo>=</mo><mn>1</mn><mo>/</mo><mo stretchy="false">(</mo><mn>4</mn><mi>π</mi><msubsup><mrow><mi>c</mi></mrow><mrow><mi>s</mi></mrow><mrow><mn>2</mn></mrow></msubsup><mo stretchy="false">)</mo></mrow></math>, which involves the speed of sound <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>c</mi><mi>s</mi></msub></math>. Since <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>c</mi><mi>s</mi><mn>2</mn></msubsup><mo>≤</mo><mn>1</mn></math> by causality, this establishes the close connection between the famous Kovtun-Son-Starinets bound and causality. Moreover, we show that the ratio of bulk to shear viscosity saturates another well-known bound for the bulk viscosity, predicted within holographic approach. We also show that the condition of isotropy of thermal radiation in the Rindler space leads to a novel sum rule relating the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>c</mi><mrow><mo stretchy="false">(</mo><mn>0</mn><mo stretchy="false">)</mo></mrow></msup><mo stretchy="false">(</mo><mi>μ</mi><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>c</mi><mrow><mo stretchy="false">(</mo><mn>2</mn><mo stretchy="false">)</mo></mrow></msup><mo stretchy="false">(</mo><mi>μ</mi><mo stretchy="false">)</mo></math> spectral densities, generally considered as independent objects, and we explicitly demonstrate its validity for conformal field theory and free massive Dirac fields in any number of dimensions. The sum rule provides the validity of Pascal law and bears some similarity with Burkhardt-Cottingham sum rule for spin-dependent parton distributions. Our result suggests a new perspective on dissipative transport phenomena in media undergoing extreme acceleration, such as quark-gluon plasma created in relativistic heavy-ion collisions.

JINR

G. Yu. Prokhorov

O.V. Teryaev

Causality, the Kovtun-Son-Starinets bound, and a novel sum rule for spectral densities

The discovery of the hidden-charm pentaquarks <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>P</mi></mrow><mrow><mi>c</mi></mrow></msub><mo stretchy="false">(</mo><mn>4312</mn><mo stretchy="false">)</mo></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>P</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>4440</mn><mo stretchy="false">)</mo></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>P</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>4457</mn><mo stretchy="false">)</mo></math> by the LHCb Collaboration are very likely to identify as the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Σ</mi><mi>c</mi><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msubsup><msup><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msup></math> molecules. A natural and crucial extension is the existence of excited molecular partners built from a ground-state charmed baryon and a radially excited anticharmed meson, namely <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Σ</mi><mi>c</mi><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msubsup><msup><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msup><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo></math> molecules. In a framework of the chiral quark model, we systematically study pion-emission decays of such excited molecules into the known ground-state <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>P</mi><mi>c</mi></msub></math> molecules. Our results show that the decay widths are sensitive to the spin structures and the coupled-channel interferences, i.e., the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Σ</mi><mi>c</mi></msub><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo><mo>/</mo><msub><mi mathvariant="normal">Σ</mi><mi>c</mi></msub><msup><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mo>*</mo></msup><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo><mo>/</mo><msubsup><mi mathvariant="normal">Σ</mi><mi>c</mi><mo>*</mo></msubsup><msup><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mo>*</mo></msup><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo><mo stretchy="false">[</mo><mn>1</mn><mo>/</mo><mn>2</mn><mo stretchy="false">(</mo><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo stretchy="false">)</mo><mo stretchy="false">]</mo></math> state decays to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>P</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>4440</mn><mo stretchy="false">)</mo></math> with a width of several MeV, while the width to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>P</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>4457</mn><mo stretchy="false">)</mo></math> is suppressed below 0.3 MeV due to destructive interference. The pion-emission decay can be the key to unveiling the excited molecular spectrum of hidden-charm pentaquarks and provides decisive experimental signatures. We expect that future experiments such as the LHCb and PANDA can verify our predictions.

Yu-Jie Tang

Wen-Yan Peng

Rui Chen

Fu-Lai Wang

Pion radiative decays of excited hidden-charm pentaquark molecules: From <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Σ</mi><mi>c</mi><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msubsup><msup><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msup><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo></math> molecules to the reported <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>P</mi><mi>c</mi></msub></math> states

We study the exclusive production of dileptons in proton-proton collisions as a probe of the proton charge-radius scale. Using a dipole form factor model, we compare the conventional choice of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi mathvariant="normal">Λ</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>=</mo><mn>0.71</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>GeV</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math> with Particle Data Group test scenarios corresponding to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>r</mi><mi>p</mi></msub><mo>=</mo><mn>0.8751</mn><mo>±</mo><mn>0.0061</mn><mtext> </mtext><mtext> </mtext><mi>fm</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>r</mi><mi>p</mi></msub><mo>=</mo><mn>0.84087</mn><mo>±</mo><mn>0.00039</mn><mtext> </mtext><mtext> </mtext><mi>fm</mi></math>, representative of the historical large radius from CODATA and smaller radius from muonic-hydrogen determinations, respectively. The sensitivity is greatest at large dilepton invariant masses and forward/backward rapidity. Fitting to the current ATLAS and CMS data within the adopted model gives <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi mathvariant="normal">Λ</mi><mn>2</mn></msup><mo>=</mo><mn>0.465</mn><mo>±</mo><mn>0.056</mn><mtext> </mtext><mtext> </mtext><msup><mi>GeV</mi><mn>2</mn></msup></math>, corresponding to an effective radius <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>r</mi><mi>p</mi></msub><mo>=</mo><mn>1.002</mn><mo>±</mo><mn>0.038</mn><mtext> </mtext><mtext> </mtext><mi>fm</mi></math>, which indicates nontrivial sensitivity on the proton-radius scale, but is not yet a definitive solution to the proton-radius puzzle. While this result depends on the theoretical model used in the calculation, it shows that exclusive dilepton production at the LHC can provide complementary model-dependent information on the proton electromagnetic form factor.

Nikhil Krishna

Mariola Kłusek-Gawenda

Rafał Staszewski

Sensitivity of the photon-induced processes to the proton charge radius