We evaluate the three-loop five-point pentagon-box-box massless integral family in the dimensional regularization scheme, via canonical differential equation. We use tools from computational algebraic geometry to enable the necessary integral reductions. The boundary values of the differential equation are determined analytically in the Euclidean region. To express the final result, we introduce a new representation of weight six functions in terms of one-fold integrals over the product of weight-three functions with weight-two kernels that are derived from the differential equation. Our work paves the way to the analytic computation of three-loop multileg Feynman integrals.

China

Yuanche Liu

Germany

Antonela Matijašić

Julian Miczajka

Yingxuan Xu

Yongqun Xu

Yang Zhang

Analytic computation of three-loop five-point Feynman integrals

We present an algorithm to extract the Coulomb branch Hasse diagram of orthosymplectic three-dimensional (3D) <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>4</mn></math> quiver gauge theories. The algorithm systematically predicts all descendant theories arising from Coulomb branch Higgsing, thereby detailing the stratification of the symplectic singularity defined by the initial Coulomb branch. Leveraging the Lie algebra isomorphism <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="fraktur">su</mi><mo stretchy="false">(</mo><mn>4</mn><mo stretchy="false">)</mo><mo>≅</mo><mi mathvariant="fraktur">so</mi><mo stretchy="false">(</mo><mn>6</mn><mo stretchy="false">)</mo></mrow></math>, we validate our algorithm via the 3D mirror of the 4D theories of class <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">S</mi></math> of such type. This comparison involves moduli spaces that admit both orthosymplectic and unitary quiver realizations, the latter being well understood via standard techniques such as decay and fission. Higgsing on the Coulomb branch of the 3D mirror or the magnetic quiver translates to Higgs branch renormalization group flows of the corresponding higher-dimensional superconformal field theories. Thus, we benchmark our method via Higgsing 6D <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mo stretchy="false">(</mo><mn>1</mn><mo>,</mo><mn>0</mn><mo stretchy="false">)</mo></math> D-type orbi-instanton theories, predicting novel Higgsing patterns involving products of interacting fixed points, and class <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">S</mi></math> theories of type <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="fraktur">so</mi><mo stretchy="false">(</mo><mn>2</mn><mi>N</mi><mo stretchy="false">)</mo></math>, demonstrating Higgsing to products of theories of types specified by Levi subalgebras of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="fraktur">so</mi><mo stretchy="false">(</mo><mn>2</mn><mi>N</mi><mo stretchy="false">)</mo></math>.

Craig Lawrie

Lorenzo Mansi

Austria

Marcus Sperling

United Kingdom

Zhenghao Zhong

Pathway to decay and fission of orthosymplectic quiver theories

A crossover involving three-fermion clusters is relevant to the hadron-quark crossover, which, if occurring in a neutron star, could naturally reproduce the dense-matter equation of state recently deduced from simultaneous observations of neutron-star masses and radii. To understand the crossover mechanism, we examine the role of tripling fluctuations induced by the formation of three-fermion clusters. The phase-shift representation of fluctuations manifests an interplay of bound and scattering states, leading to nonmonotonic momentum distributions of baryonlike clusters and peaked sound speed at finite densities. We demonstrate them by applying our approach to a nonrelativistic system of one-dimensional three-color fermions analogous to the hadron-quark matter.

Japan

Hiroyuki Tajima

Kei Iida

Toru Kojo

Haozhao Liang

Tripling Fluctuations and Peaked Sound Speed in Fermionic Matter

While there is a general consensus about the structure of one qubit operations in topological quantum computer, two qubits are as usual a more difficult and complex story of different attempts with varying approaches, problems and effectiveness. In this paper we discuss how to construct an efficient realization of a two qubit gate in topological quantum computer, by using principle of cabling from the knot theory. This allows one to construct a braiding of cables dependent on the parameters of the theory where there is a low probability of moving out of computational space (high fidelity of operation) with a non-trivial entangling two-qubit operation. We also present some examples of these operations for different parameters of the theory.

Russia

Sergey Mironov

Andrey Morozov

Entangling gates from cabling of knots

We introduce building blocks for the cluster hadronization model in light of a new structure, focusing on cluster fission and cluster decay. We propose theoretically motivated matrix elements for cluster fission and decay as building blocks and study some first phenomenological implications at different energies. In particular we develop a set of observables which can be used to dissect the hadronization history and have constraining power on the individual building blocks. Our analysis will be completed by including colour reconnection in a follow-up work.

Stefan Gieseke

Stefan Kiebacher

Simon Plätzer

Jan Priedigkeit

Phenomenological constraints of the building blocks of the cluster hadronization model

The Event Horizon Telescope (EHT) imaged black holes M87 $$^*$$ (angular diameter $$\theta _d = 42 \pm 3\,\upmu \text {as},$$ mass $$\sim 6.5 \times 10^9\,M_\odot )$$ and Sgr A $$^*$$ $$(\theta _d = 48.7 \pm 7\,\upmu \text {as},$$ shadow deviation $$\delta \approx -0.08^{+0.09}_{-0.09}$$ (VLTI), $$-0.04^{+0.09}_{-0.10})$$ (Keck). These observations enable tests of gravity in strong regimes. We propose a rotating non-commutative inspired Kiselev black hole (RNKBH), incorporating dark energy $$(\omega )$$ and non-commutative $$(\Theta )$$ parameters, extending Kerr solutions. Our analysis reveals that $$\omega = -2/3$$ allows larger $$\Theta $$ but requires $$a \ge 0.16M$$ to maintain horizons. Shadow calculations show significant deviations from Kerr predictions: for $$\Theta = 0.001-0.005M^2,$$ shadows shrink by 8-15% and distortion increases by 20-35% for rapidly spinning $$(a > 0.5M)$$ black holes. The $$\omega = -2/3$$ exhibits shadow squeezing near the cosmological horizon. We compute shadow observables and compare them with EHT data. For Sgr A $$^*$$ $$(50^\circ $$ inclination), the bounds are $$0.001497 \le \Theta \le 0.002868\,M^2$$ at $$a =0.9146$$ $$(\omega = -2/3)$$ . For M87 $$^*$$ $$(17^\circ )$$ , $$0 \le \Theta \le 0.004993 \,M^2$$ at $$a=0.0.6167$$ $$(\omega = -2/3)$$ . While EHT cannot yet distinguish RNKBH from Kerr BH, our results highlight its viability as an astrophysical candidate.

Fazlay Ahmed

India

Heena Ali

Qiang Wu

Tao Zhu

South Africa

Sushant Ghosh

Shadows of rotating non-commutative Kiselev black holes: constraints from EHT observations of M87* and Sgr A*

We examine the sterile neutrino dark matter production in the primordial plasma with lepton asymmetry unequally distributed over different neutrino flavors. We argue that with the specific flavor fractions, one can mitigate limits from the Big Bang Nucleosynthesis on the sterile-active neutrino mixing angle and sterile neutrino mass. It happens due to cancellation of the neutrino flavor asymmetries in active neutrino oscillations, which is more efficient in the case of inverse hierarchy of active neutrino masses and does not depend on the value of CP-phase. This finding opens a window of lower sterile-active mixing angles. Likewise, we show that, with lepton asymmetry disappearing from the plasma at certain intermediate stages of the sterile neutrino production, the spectrum of produced neutrinos becomes much colder, which weakens the limits on the model parameter space from observations of cosmic small-scale structures (Ly- <italic>&#945;</italic> forest, galaxy counts, etc.). This finding reopens the region of lighter sterile neutrinos. The new region may be explored with the next generation of X-ray telescopes searching for the inherent peak signature provided by the dark matter sterile neutrino radiative decays in the Galaxy.

Dmitry Gorbunov

Dmitry Kalashnikov

George Krugan

Playing with lepton asymmetry at the resonant production of sterile neutrino dark matter

In this paper, we investigate a <math altimg='si1.svg'><mo stretchy='false'>(</mo><mn>1</mn><mo linebreak='badbreak' linebreakstyle='after'>+</mo><mn>3</mn><mo stretchy='false'>)</mo></math>-dimensional static Friedmann-Robertson-Walker (FRW) space-time, pierced by a cosmic string. Our analysis begins with a detail study of the geodesic motion of photon rays in this curved background, focusing on the behavior of the associated effective potential. This allows us to understand how the cosmic string and curvature of space-time influence the trajectories of light rays. Moving beyond ray optics, we explore wave optics by solving the covariant Helmholtz equation in this gravitational setting. By transforming the resulting radial equation into a Schr&#246;dinger-like form, we extract an effective potential and derive a frequency-dependent refractive index. This refractive index shows the combined effects of the cosmic string and the curvature parameter, showing their influence on the wave propagation. Furthermore, we extend our study to a <math altimg='si2.svg'><mo stretchy='false'>(</mo><mn>1</mn><mo linebreak='badbreak' linebreakstyle='after'>+</mo><mn>2</mn><mo stretchy='false'>)</mo></math>-dimensional space-time with disclinations, where we analyze the wave optics phenomena. Through the Helmholtz equation in this lower-dimensional case, we determine the refractive index and discuss how it is affected by the geometric parameters of this lower-dimensional space-time. Through both geometric and wave optics approaches, our work provides a comprehensive understanding of how topological defects and curvature impact geometric and physical optics in curved space-time of three- and four-dimensions.

Faizuddin Ahmed

Algeria

Abdelmalek Bouzenada

Ray and wave dynamics in a static FRW spacetime with conical singularity

The Event Horizon Telescope's 2024 observations report a shift in the position angle of the brightness asymmetry in M87*, revealing time variability in the black hole's image. In this analysis, we investigate the time-dependent of a Vaidya black hole. By introducing a mass function that increases linearly with time, along with a conformal transformation, we derive the conformal Vaidya metric and define a new time coordinate <math altimg='si1.svg'><msub><mrow><mi>t</mi></mrow><mrow><mi>c</mi></mrow></msub></math>. Using the semi-analytical approach, we analyze the ray trajectories and radiation flux of the Vaidya black hole in the background of a thin accretion disk. We discuss how the observed flux in the Vaidya spacetime evolves as a function of the new time coordinate <math altimg='si1.svg'><msub><mrow><mi>t</mi></mrow><mrow><mi>c</mi></mrow></msub></math>. The results show that the facula on the observable plane undergoes radial displacement as <math altimg='si1.svg'><msub><mrow><mi>t</mi></mrow><mrow><mi>c</mi></mrow></msub></math> increases, revealing the time-dependent evolution of black hole images.

Yu Liang

Sen Guo

Brazil

Kai Lin

Yu-Hao Cui

Yu-Xiang Huang

Tao Yu

Image of the time-dependent black hole

We argue for the existence of bounds on the tensions of $\textit{p}$-branes in de Sitter space in terms of the Hubble rate and the strength of a class of Chern-Simons-like couplings. The world-volume couplings involve Abelian 1-form gauge fields in the bulk and possibly field strengths intrinsic to the brane. In many cases these couplings are the D-brane Chern-Simons terms present in string theory, while in other cases they are the interactions of axion domain walls with U(1) fields. Our arguments use the same logic and assumptions as the recent Festina Lente proposal (thus utilizing the properties of Nariai de Sitter black holes) and generalize it to extended objects, thereby providing a bottom-up set of constraints independent of any particular UV completion. We compare these bounds to the properties of (wrapped) D-branes in Type II string theory in the weak coupling limit, under the assumption that these properties are not modified significantly in de Sitter constructions. We find that all constraints are satisfied by D-branes, providing further evidence for the Festina Lente conjecture. For the particular case of 2-branes with Chern-Simons interactions we obtain a bound, which however can be evaded if the theory contains a light axion. Similarly, we find the bounds do not apply to axion domain walls due to the presence of the axion.

Saquib Hassan

Georges Obied

John March-Russell

De Sitter space constraints on brane tensions and couplings