Modern radio interferometers are increasingly challenged by fast transient events, complex radio-frequency interference (RFI), and observing conditions in which near-field and far-field emitters may coexist. Although classical direction-of-arrival (DOA) techniques can achieve high angular resolution, they are often developed for specific array geometries, tend to focus on single-source settings, and usually provide little information about uncertainty. Imaging-based methods, while powerful, are computationally demanding and can introduce delays that are not well suited to real-time transient astronomy.

Algeria

Halim Zeghdoudi

Türkiye

Fatih Tank

Bayesian polarimetric multi-source direction-of-arrival estimation for transient astronomy with sparse radio interferometric subarrays

In this work, we present the refinement of axion double level crossings within the context of multi-axion mass mixing, specifically focusing on cases where the number of axions exceeds two. Our investigation reveals that double level crossings are a common phenomenon in the mass mixing of the <math altimg='si15.svg'><msub><mi>Z</mi><mi mathvariant='script'>N</mi></msub></math> axion and axion-like particles. Physically, these double level crossings involve a first level crossing at high temperatures followed by a second level crossing induced by the <math altimg='si15.svg'><msub><mi>Z</mi><mi mathvariant='script'>N</mi></msub></math> axion mass transition at <italic>T</italic> <inf>QCD</inf>. We introduce the general model for double level crossings, along with several toy examples, and redefine the light and heavy axion scenarios. In the light axion scenario, double level crossings can occur multiple times in the large <math altimg='si12.svg'><mi mathvariant='script'>N</mi></math> limit. However, excessively large values of <math altimg='si12.svg'><mi mathvariant='script'>N</mi></math> may also prevent the occurrence of double level crossings. Conversely, in the heavy axion scenario, excessively small <math altimg='si12.svg'><mi mathvariant='script'>N</mi></math> may similarly prevent their occurrence. Our findings also have some intriguing implications for axion cosmology.

China

Hai-Jun Li

Wei Chao

Huai-Ke Guo

Yu-Feng Zhou

Completing axion double level crossings

We study the conformal field theory defined by the fourth-order operator on four-dimensional manifolds with boundaries, reformulating it through an auxiliary field so that the dynamics become second order. Within this framework, we compute the heat kernel of <math altimg='si1.svg'><msup><mo>&#9633;</mo><mn>2</mn></msup></math> in flat space exactly, together with the associated Seeley-DeWitt coefficients for a broad class of non-standard boundary conditions. On curved backgrounds, we further construct the Weyl-invariant completion of the auxiliary field action with boundary terms and identify the corresponding conformal boundary conditions. Finally, we compute the boundary charges in the trace anomaly from the displacement operator correlators.

France

Gregorio Paci

Russia

Sergey N. Solodukhin

Auxiliary-field formalism for higher-derivative boundary CFTs

It was shown roughly thirty years ago that the density correlations of eigenvalues of large random matrices display a universal form, independent of most of the details of the distribution of the random matrix itself. We show that when the matrix elements evolve according to a Dyson Brownian motion, dynamical correlations retain a large degree of the universality found at equal times when expressed in terms of the characteristics of some partial differential equation in the complex plane.

Kirone Mallick

Colombia

Gabriel Téllez

Japan

Frédéric van Wijland

Weakly universal dynamical correlations between eigenvalues of large random matrices

This work presents a new class of exact solutions characterizing anisotropic dense objects in the Rastall-Rainbow theory under the effects of charged fluid content. For this, we make the assumption that the matter distribution is spherically symmetric and determine the analogous field equations coupled with the anisotropic profile. By using known radial metric functions into the anisotropic expression, we get differential equations which are integrated to determine the time component involving multiple integration constants. The interior solutions are smoothly matched with an appropriate exterior metric at the surface of a compact star to figure out these constants. These constants also accommodate the Rastall parameter by imposing the boundary condition of zero radial pressure. Afterwards, we explore the physical characteristics and important stability criteria for the developed models under the observed data from a pulsar SMC X-4. Our models are deduced to be well-aligned with the requirements needed for these stellar structures to be physically realistic under certain parametric choices.

Pakistan

Azerbaijan

Tayyab Naseer

Fatima Chand

M. Sharif

Saudi Arabia

Wedad Albalawi

Jordan

Kottakkaran Sooppy Nisar

Omer A. Magzoub

Mathematical modeling of anisotropic compact objects and role of fluid-geometry coupling under charged matter distribution

In this paper, we derive characteristic identities for the split Casimir operator of the Lie algebra <italic>so</italic> <inf>2<italic>r</italic></inf> in tensor products of spinor representations of the same and opposite chiralities. Using these identities, we explicitly construct projectors onto invariant subspaces of this operator and compute their traces. The results obtained allow us to derive explicit expressions for the colour factors of ladder Feynman diagrams in gauge theories with gauge group Spin(2 <italic>r</italic>).In addition, we obtain a new form of a solution to the Yang-Baxter equation that is invariant under the action of the Lie algebra <italic>so</italic> <inf>2<italic>r</italic></inf> in spinor representations.

A.P. Isaev

A.A. Provorov

Split Casimir operator of the Lie algebra <italic>so</italic> <inf>2<italic>r</italic></inf> in spinor representations, colour factors, and the Yang-Baxter equation

Given the 3 × 3 Cabibbo-Kobayashi-Maskawa (CKM) quark flavor mixing matrix <italic>V</italic>, we define a new set of rephasing invariants in terms of the &#8220;trios&#8221; of its nine elements: <math altimg='si1.svg'><mrow><msubsup><mi>&#9674;</mi><mrow><mi>&#945;</mi><mi>&#946;</mi><mi>&#947;</mi></mrow><mrow><mi>i</mi><mi>j</mi><mi>k</mi></mrow></msubsup><mo>&#8801;</mo><mrow><mo>(</mo><msub><mi>V</mi><mrow><mi>&#945;</mi><mi>i</mi></mrow></msub><msub><mi>V</mi><mrow><mi>&#946;</mi><mi>j</mi></mrow></msub><msub><mi>V</mi><mrow><mi>&#947;</mi><mi>k</mi></mrow></msub><mo>)</mo></mrow><mo linebreak='goodbreak'>/</mo><mi>det</mi><mi>V</mi></mrow></math> with <italic>&#945;</italic>&#8239;&#8800;&#8239; <italic>&#946;</italic>&#8239;&#8800;&#8239; <italic>&#947;</italic> and <italic>i</italic>&#8239;&#8800;&#8239; <italic>j</italic>&#8239;&#8800;&#8239; <italic>k</italic> running respectively over ( <italic>u, c, t</italic>) and ( <italic>d, s, b</italic>). We find that <math altimg='si2.svg'><mrow><mrow><mrow><mi mathvariant='normal'>I</mi></mrow><mi>m</mi></mrow><msubsup><mi>&#9674;</mi><mrow><mi>&#945;</mi><mi>&#946;</mi><mi>&#947;</mi></mrow><mrow><mi>i</mi><mi>j</mi><mi>k</mi></mrow></msubsup><mo linebreak='goodbreak'>=</mo><mo>&#8722;</mo><mi mathvariant='script'>J</mi></mrow></math> holds, where <math altimg='si3.svg'><mi mathvariant='script'>J</mi></math> is the well-known Jarlskog invariant of weak CP violation. Analogous rephasing invariants <math altimg='si4.svg'><mrow><msubsup><mi>&#10731;</mi><mrow><mi>&#945;</mi><mi>&#946;</mi><mi>&#947;</mi></mrow><mrow><mi>i</mi><mi>j</mi><mi>k</mi></mrow></msubsup><mo>&#8801;</mo><mrow><mo>(</mo><msub><mi>U</mi><mrow><mi>&#945;</mi><mi>i</mi></mrow></msub><msub><mi>U</mi><mrow><mi>&#946;</mi><mi>j</mi></mrow></msub><msub><mi>U</mi><mrow><mi>&#947;</mi><mi>k</mi></mrow></msub><mo>)</mo></mrow><mo linebreak='goodbreak'>/</mo><mi>det</mi><mi>U</mi></mrow></math> can be defined for the 3&#8239;&#215;&#8239;3 Pontecorvo-Maki-Nakagawa-Sakata (PMNS) lepton flavor mixing matrix <italic>U</italic>, where <italic>&#945;</italic>&#8239;&#8800;&#8239; <italic>&#946;</italic>&#8239;&#8800;&#8239; <italic>&#947;</italic> and <italic>i</italic>&#8239;&#8800;&#8239; <italic>j</italic>&#8239;&#8800;&#8239; <italic>k</italic> run respectively over ( <italic>e, &#956;, &#964;</italic>) and (1, 2, 3). Taking into account small non-unitarity of <italic>U</italic> based on the canonical seesaw mechanism for neutrino mass generation, we calculate <math altimg='si5.svg'><mrow><mrow><mrow><mi mathvariant='normal'>I</mi></mrow><mi>m</mi></mrow><msubsup><mi>&#10731;</mi><mrow><mi>&#945;</mi><mi>&#946;</mi><mi>&#947;</mi></mrow><mrow><mi>i</mi><mi>j</mi><mi>k</mi></mrow></msubsup></mrow></math> with the help of a full Euler-like block parametrization of the seesaw flavor structure and demonstrate that their leading terms converge to a universal invariant <math altimg='si6.svg'><msub><mi mathvariant='script'>J</mi><mi>&#957;</mi></msub></math> in the unitarity limit of <italic>U</italic>.

Shu Luo

Zhi-zhong Xing

New rephasing invariants and CP violation built from the trios of the CKM or PMNS matrix elements

We derive general formulas for three flavor fractions <math altimg='si1.svg'><mrow><mo>(</mo><msub><mi>&#951;</mi><mi>e</mi></msub><mo>,</mo><msub><mi>&#951;</mi><mi>&#956;</mi></msub><mo>,</mo><msub><mi>&#951;</mi><mi>&#964;</mi></msub><mo>)</mo></mrow></math> of the high-energy neutrinos originating from a remote astrophysical source by using their flavor ratios <math altimg='si2.svg'><mrow><mo>(</mo><msub><mi>f</mi><mi>e</mi></msub><mo>,</mo><msub><mi>f</mi><mi>&#956;</mi></msub><mo>,</mo><msub><mi>f</mi><mi>&#964;</mi></msub><mo>)</mo></mrow></math> observed at a neutrino telescope, and diagnose a potential divergence associated with <math altimg='si3.svg'><msub><mi>&#951;</mi><mi>&#956;</mi></msub></math> and <math altimg='si4.svg'><msub><mi>&#951;</mi><mi>&#964;</mi></msub></math> as an unavoidable consequence of the <math altimg='si5.svg'><mrow><mi>&#956;</mi><mspace width='0.16em' /><mo linebreak='goodbreak'>&#8722;</mo><mspace width='0.16em' /><mi>&#964;</mi></mrow></math> interchange symmetry exhibiting in the 3&#8239;&#215;&#8239;3 lepton flavor mixing matrix <italic>U</italic>. We present a complete set of analytical expressions for <math altimg='si1.svg'><mrow><mo>(</mo><msub><mi>&#951;</mi><mi>e</mi></msub><mo>,</mo><msub><mi>&#951;</mi><mi>&#956;</mi></msub><mo>,</mo><msub><mi>&#951;</mi><mi>&#964;</mi></msub><mo>)</mo></mrow></math> as functions of two typical <math altimg='si5.svg'><mrow><mi>&#956;</mi><mspace width='0.16em' /><mo linebreak='goodbreak'>&#8722;</mo><mspace width='0.16em' /><mi>&#964;</mi></mrow></math> symmetry breaking parameters in the standard parametrization of <italic>U</italic>, and apply it to the recent IceCube all-sky neutrino flux data ranging from 5 TeV to 10 PeV in the assumption that the relevant sources have a common flavor composition. We also explain why only <math altimg='si6.svg'><msub><mi>&#951;</mi><mi>e</mi></msub></math> and <math altimg='si7.svg'><mrow><msub><mi>&#951;</mi><mi>&#956;</mi></msub><mo linebreak='goodbreak'>+</mo><msub><mi>&#951;</mi><mi>&#964;</mi></msub></mrow></math> can be extracted from a precision measurement of <math altimg='si8.svg'><msub><mi>f</mi><mi>e</mi></msub></math> and <math altimg='si9.svg'><mrow><msub><mi>f</mi><mi>&#956;</mi></msub><mo linebreak='goodbreak'>=</mo><msub><mi>f</mi><mi>&#964;</mi></msub></mrow></math> in the exact <math altimg='si5.svg'><mrow><mi>&#956;</mi><mspace width='0.16em' /><mo linebreak='goodbreak'>&#8722;</mo><mspace width='0.16em' /><mi>&#964;</mi></mrow></math> flavor symmetry limit.

Potential divergence in tracing <italic>&#956;</italic> and <italic>&#964;</italic> flavors of astrophysical neutrinos

F-theory compactifications with a nontrivial Mordell-Weil group realize abelian gauge symmetry through rational sections, but their consistency is ultimately a statement about the quantum effective action. We show that compactification on a circle makes this statement concrete: the quantized, parity-odd Chern-Simons couplings of the resulting three-dimensional theory provide a one-loop exact and scheme-independent encoding of all local four-dimensional abelian anomalies, including the mixed gauge-gravitational terms, together with their Green-Schwarz cancellation. We determine these Chern-Simons couplings in two logically independent ways, first from flux-induced terms in the M-theory dual description, and second from an explicit one-loop integration over the complete massive spectrum, including Kaluza-Klein towers and Coulomb-branch states. The agreement fixes all normalizations and clarifies how large gauge transformations reorganize the spectrum. We then show compatibility with type IIB modular duality once the known ten-dimensional duality counterterm is included, and we present a fully explicit rank-two example over projective three-space.

Canada

United Kingdom

Belgium

Mir Faizal

Arshid Shabir

Chern-Simons couplings, modular duality, and anomaly cancellation in abelian F-theory

We applied the exact Andreev soft-wall holographic model to investigate phase transitions in rotating strongly interacting matter at high and low densities. Using the dual description of hadronic matter and quark-gluon plasma via thermal and charged black holes in five-dimensional AdS space with cylindrical symmetry, we find that for relativistic rotations exceeding 16% of the speed of light, crossover transitions emerge in the low-density regime up to a critical baryon chemical potential <italic>&#956;<inf>CPB</inf></italic>. These smooth transitions, governed by the negative QCD <italic>&#946;</italic>-function, describe a mixed phase of confined and deconfined matter with different angular momenta evolving into a pure plasma at very high temperatures. For <italic>&#956;</italic>&#8239;&#8805;&#8239; <italic>&#956;<inf>CPB</inf></italic>, first-order transitions dominate, following the critical-temperature curve of non-rotating matter. The critical point separating the low-density crossovers from high-density first-order transitions is numerically estimated as <math altimg='si32.svg'><mrow><mrow><mo>(</mo><msub><mi>&#956;</mi><mrow><mi>C</mi><mi>P</mi><mi>B</mi></mrow></msub><mo>,</mo><msub><mi>T</mi><mrow><mi>C</mi><mi>P</mi></mrow></msub><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><mrow><mo>(</mo><mn>363.554</mn><mo>,</mo><mn>58.507</mn><mo>)</mo></mrow><mspace width='0.16em' /><mtext>MeV</mtext></mrow></math>.

Brazil

Octavio C․ Junqueira

Roldao Da Rocha

Phase transitions at high and low densities for a rotating QCD matter from holography