We propose a field-theoretic framework for ideal hydrodynamics of charged relativistic fluids formulated in terms of a complex scalar field defined on a spacelike hypersurface comoving with the fluid. In the normal phase, the dynamics of charge-carrying fluids is constrained by the restrictive chemical shift symmetry, which locks charges to fixed positions in the comoving plane as they are transported through space by the fluid’s motion. On the other hand, in the superfluid phase, the chemical shift symmetry is relaxed to a constant shift, allowing charges to redistribute freely across the comoving hypersurface. We demonstrate that both models recover the respective nonlinear hydrodynamic equations and provide explicit expressions for the collective variables of hydrodynamics in terms of the theory’s fields. Introduced models provide a UV completion to the effective field theories of hydrodynamics constructed in terms of the Goldstone fields. Finally, we propose a relativistic fracton fluid phase as a natural interpolation between the normal and superfluid phases, in which the mobility of elementary charges is constrained by a linear shift symmetry in the comoving space.

Poland

Aleksander Głódkowski

A complex scalar field theory for charged fluids, superfluids, and fracton fluids

Changes in magnetic helicity are often discussed across a variety of fields, from condensed matter physics to early universe cosmology. It is frequently stated that the helicity change is given by the integral of the gauge field strength tensor and its dual over spacetime, ∫ $\textit{F}$ ∧ $\textit{F}$. However, this is incorrect when magnetic monopoles once existed in the spacetime. In this paper, we show the correct formula of the helicity change in such a case for the Maxwell theory with the magnetic monopoles. We also discuss what happens when we embed the Maxwell theory with magnetic monopoles into non-Abelian gauge theories. We show that a similar formula holds for the ’t Hooft-Polyakov monopole. In particular, we find the winding numbers and the zeroes of the Higgs field in the non-Abelian gauge theory play a crucial role in the helicity change. The same discussion is also applicable to the electroweak theory, and we discuss the implication of our findings to the baryon number change via the chiral anomaly in the early universe.

Japan

Hajime Fukuda

Yuta Hamada

China

Kohei Kamada

Kyohei Mukaida

South Korea

Fumio Uchida

Magnetic helicity, magnetic monopoles, and Higgs winding

We propose a novel topological vertex formalism for 5d $$ \mathcal{N}=1 $$ SU($\textit{N}$) gauge theory with a hypermultiplet in the symmetric tensor representation, whose Type IIB brane construction involves an NS5-brane attached to an O7 -plane. Inspired by the identification O7 ∼ ℤ + 4D7, we introduce two new types of vertices: the ℤ -vertex, which implements the ℤ orbifold action, and the FD-vertex, which encodes the monodromy cut induced by the O7 -plane. This formalism generalizes the framework presented in (2025) 182 and establishes a systematic method for computing partition functions for 5-brane configurations that incorporate an O7 -plane. The resulting partition functions are expressed as sums over Young diagrams, providing a powerful computational tool for studying such gauge theories.

Sung-Soo Kim

Xiaobin Li

Futoshi Yagi

Rui-Dong Zhu

Topological Vertex for Symmetric matter

In this work, we employ the Tannaka-Krein reconstruction to compute the quantum double 𝒟(𝒢) of a finite 2-group 𝒢 as a Hopf monoidal category. We also construct a 3+1D lattice model from the Dijkgraaf-Witten TQFT functor for the 2-group 𝒢, generalizing Kitaev’s 2+1D quantum double model. Notably, the string-like local operators in this lattice model are shown to form 𝒟(𝒢). Specializing to 𝒢 = ℤ , we demonstrate that the topological defects in the 3+1D toric code model are modules over 𝒟(ℤ ).

Mo Huang

Finite 2-group gauge theory and its 3+1D lattice realization

We investigate a theory of SU(9) dark grand unification, where dark matter consists of asymmetric dark baryons from the Sp(4) dark QCD sector. By unifying the dark color gauge group with the Standard Model gauge group, the asymmetry generation in both sectors originates from a common process that preserves a U(1) symmetry, resulting in comparable number densities. Furthermore, thanks to dark grand unification, the Sp(4) dark QCD sector shares a similar matter content with the QCD sector, leading to comparable running of the gauge couplings from the scale as high as 10 GeV. This predicts a dark color confinement scale and thus dark baryon masses around the GeV scale, comparable to visible baryon masses. Together with the similar number densities, the model provides an explanation for the observed similarity between the energy densities of dark matter and baryons, $\textit{ρ}$ ≈ 5 $\textit{ρ}$ . The model also features some novel phenomenology, including a GeV-scale flavored dark QCD sector with diquark dark baryons and light dark mesons. The interaction between the dark sector and the visible sector occurs via a new $\textit{Z′}$ boson with a mass of $$ \mathcal{O}(10) $$ TeV, which could be searched for at future hadron colliders. We also briefly discuss an SU(8) dark grand unified theory featuring an SU(3) dark QCD sector.

Germany

Yi Chung

Comparable dark matter and baryon energy densities from dark grand unification

We develop a twistor-space framework to compute boundary correlators via a boundary limit of nested Penrose transforms in (A)dS . Starting from correlators of (anti-)self-dual bulk fields, the boundary limit reproduces the correlators of the dual conserved currents; we demonstrate this explicitly for two- and three-point functions. The two-point correlator is rendered finite by working in Euclidean signature. At three points, we obtain compact rational twistor-space representatives obeying a double-copy relation, thereby clarifying the twistor-space origin of the results in . We further extend the analysis to non-conserved currents with integer conformal dimension, dual to massive bulk fields, as well as to the free scalar.

United Kingdom

Mariana Carrillo González

Théo Keseman

Spinning boundary correlators from (A)dS4 twistors

We present a calculation of the thrust distribution in Higgs decays to quarks and gluons, $$ H\to b\overline{b} $$ , $$ H\to c\overline{c} $$ , and $\textit{H}$ → $\textit{gg}$, including the resummation of large logarithmic corrections that arise in the two-particle limit at next-to-next-to-leading logarithmic (NNLL) accuracy, and match it to fixed-order results for three-particle decays at next-to-next-to-leading order (NNLO) in the strong coupling. The resummation is performed analytically within the A framework and combined with the fixed-order results using the logR matching technique. The fixed-order calculation is carried out numerically with the NNLO parton-level event generator, using the antenna subtraction method. We perform detailed cross-validation in the two-particle region, demonstrating that the expansion of the NNLL resummed result correctly reproduces the logarithmic structure of the fixed-order calculation to $$ \mathcal{O}\left({\alpha}_{\textrm{s}}^3\right) $$ , up to a predictable N LL term at $$ \mathcal{O}\left({\alpha}_{\textrm{s}}^3L\right) $$ . In addition to providing the first NNLO+NNLL accurate predictions for the thrust distribution in Higgs decays to quarks and gluons, we analytically extract the $$ \mathcal{O}\left({\alpha}_{\textrm{s}}^2\right) $$ hard-virtual correction $\textit{c}$ and the $$ {\alpha}_{\textrm{s}}^3L $$ term $\textit{G}$ in both the $$ H\to q\overline{q} $$ ($\textit{q}$ = $\textit{b}$, $\textit{c}$) and $\textit{H → gg}$ decay channels.

Elliot Fox

Switzerland

Aude Gehrmann-De Ridder

Thomas Gehrmann

Nigel Glover

Matteo Marcoli

Christian Preuss

The thrust distribution at NNLO+NNLL in Higgs decays to quarks and gluons

Within the framework of nonrelativistic quantum chromodynamics (NRQCD) factorization, we compute the $$ \mathcal{O}\left({v}^4\right) $$ relativistic corrections to the fragmentation of a heavy quark into the color-singlet $$ {}^1{S}_0^{\left[1\right]} $$ and $$ {}^3{S}_1^{\left[1\right]} $$ quarkonium states. Using the Collins-Soper definition of the fragmentation function, we reproduce the known $$ \mathcal{O}\left({v}^2\right) $$ results. We find that the $$ \mathcal{O}\left({v}^4\right) $$ correction gives a positive contribution relative to the leading order result over a wide range of the light-cone momentum fraction $\textit{z}$, while its magnitude remains much smaller than that of the $$ \mathcal{O}\left({v}^2\right) $$ correction. This behavior indicates a good convergence of the NRQCD relativistic expansion in this process. We further extend the calculation to the fragmentation functions in the unequal-mass case at $$ \mathcal{O}\left({v}^4\right) $$ and obtain the corresponding analytical expressions.

Sai Cui

Yi-Jie Li

Guang-Zhi Xu

Kui-Yong Liu

Order-$\textit{v}$ 4 corrections to heavy quark fragmentation to $\textit{S}$-wave heavy quarkonium

We present a unified free field realization of the Ding-Iohara algebra at arbitrary levels, which satisfies a generalized form of the Serre relations. This realization, constructed using six free boson fields, arises from a specialized factorization of the structure function in the defining relations of the algebra. Based on this construction, we then develop intertwining operators for the Ding-Iohara algebra.

Zitao Chen

Xiang-Mao Ding

Free field realization of the Ding-Iohara algebra at general levels

We study fully BPS and a broad class of half-BPS stationary configurations of four-dimensional Euclidean $$ \mathcal{N}=2 $$ supergravity with higher-derivative interactions. Working within the off-shell conformal supergravity framework of de Wit and Reys (arXiv:1706.04973), we analyse the complete set of Killing spinor equations and obtain the corresponding algebraic and differential constraints. We further derive the Euclidean attractor equations and evaluate the Wald entropy for the fully BPS AdS × $\textit{S}$ background. For half-BPS stationary configurations, we obtain the generalized stabilization equations expressing all fields in terms of harmonic functions on three-dimensional flat base space, extending the Lorentzian analysis of Cardoso et al. ( ) to the Euclidean signature. Our results provide a framework for studying supersymmetric saddles and computing the gravitational indices entirely within Euclidean higher-derivative supergravity, without recourse to analytic continuation.

Soumya Adhikari

India

Abhinava Bhattacharjee

Amitabh Virmani

BPS solutions of 4d Euclidean $$ \mathcal{N}=2 $$ supergravity with higher derivative interactions