It’s widely recognized that the free energy landscape captures the essentials of thermodynamic phase transitions. In this work, we extend the findings of [1] by incorporating the nonextensive nature of black hole entropy. Specifically, the connection between black hole phase transitions and the winding number of Riemann surfaces derived through complex analysis is extended to the Rényi entropy framework. This new geometrical and nonextensive formalism is employed to predict the phase portraits of charged-flat black holes within both the canonical and grand canonical ensembles. Furthermore, we elucidate novel relations between the number of sheets comprising the Riemann surface of the Hawking–Page and Van der Waals transitions and the dimensionality of black hole spacetimes. Notably, these new numbers are consistent with those found for charged-AdS black holes in Gibbs–Boltzmann statistics, providing another significant example of the potential connection between the cosmological constant and the nonextensive Rényi parameter.

Morocco

Riemann surfaces and winding numbers of Rényi phase structure of charged-flat black holes

In the present paper, the dual symmetries of dense quark matter phase diagram found in some massless three- and two-color NJL models in the mean field approximation have been shown to exist at a more fundamental level as dual transformations of fields and chemical potentials leaving the Lagrangian invariant. As a result, the corresponding dual symmetries of the full phase diagram can be shown without any approximation. And it has been shown not only in the NJL models, but also in framework of two- and three-color massless QCD itself. This is quite interesting, since one might say that it is not very common to show something completely non-perturbatively in QCD.

Russia

Dual symmetries of dense isotopically and chirally asymmetric QCD

Antinuclei in our Galaxy may stem either from annihilation or decay of dark matter, or from collisions of cosmic rays with the interstellar medium, which constitute the background of indirect dark matter searches. Understanding the formation mechanism of (anti)nuclei is crucial for setting limits on their production in space. Coalescence models, which describe the formation of light nuclei from final-state interaction of nucleons, have been widely employed in high-energy collisions. In this work, we introduce ToMCCA (Toy Monte Carlo Coalescence Afterburner), which allows for detailed studies of the nuclear formation processes without the overload of general-purpose event generators. ToMCCA contains parameterizations of the multiplicity dependence of the transverse momentum distributions of protons and of the baryon-emitting source size, extracted from ALICE measurements in pp collisions at  $$\sqrt{s} = 5 - 13$$  <math> <mrow> <msqrt> <mi>s</mi> </msqrt> <mo>=</mo> <mn>5</mn> <mo>-</mo> <mn>13</mn> </mrow> </math>   TeV, as well as of the event multiplicity distributions, taken from the EPOS event generator. ToMCCA provides predictions of the deuteron transverse momentum distributions, with agreement of  $$\sim 5\%$$  <math> <mrow> <mo>∼</mo> <mn>5</mn> <mo>%</mo> </mrow> </math>   with the experimental data. The results of ToMCCA show that the coalescence mechanism in pp collisions depends only on the event multiplicity, not on the collision system or its energy. This allows the model to be utilized for predictions at lower center-of-mass collision energies, which are the most relevant for the production of antinuclei from processes related to dark matter. This model can also be extended to heavier nuclei as long as the target nucleus wavefunction and its Wigner function are known.

Germany

CERN

ToMCCA: a Toy Monte Carlo Coalescence Afterburner

The Pauli Exclusion Principle (PEP) appears from fundamental symmetries in quantum field theories, but its physical origin is still to be understood. High-precision experimental searches for small PEP violations permit testing key assumptions of the Standard Model with high sensitivity. We report on a dedicated measurement with Gator, a low-background, high-purity germanium detector operated at the Laboratori Nazionali del Gran Sasso, aimed at testing PEP-violating atomic transitions in lead. The experimental technique, relying on forming a new symmetry state by introducing electrons into the pre-existing electron system through a direct current, satisfies the conditions of the Messiah-Greenberg superselection rule. No PEP violation has been observed, and an upper limit on the PEP violation probability of  $$\beta ^2/2 &lt; 4.8 \cdot 10^{-29}$$  <math> <mrow> <msup> <mi>β</mi> <mn>2</mn> </msup> <mo>/</mo> <mn>2</mn> <mo>&lt;</mo> <mn>4.8</mn> <mo>·</mo> <msup> <mn>10</mn> <mrow> <mo>-</mo> <mn>29</mn> </mrow> </msup> </mrow> </math>   (90% CL) is set. This improves the previous constraint from a comparable measurement by more than one order of magnitude.

Switzerland

Italy

Search for Pauli Exclusion Principle violations with Gator at LNGS

We investigated the Strong Cosmic Censorship (SCC) conjecture in Einstein–Power–Maxwell–de Sitter (EPMdS) black holes by analyzing the quasinormal modes (QNMs) of a massless neutral scalar field perturbation. Using the pseudospectral method, we calculated the QNM frequencies across various cosmological constants and nonlinear electromagnetic parameters. Our results show that for black holes far from extremality, the lowest QNM frequency  $$-\text {Im} (\omega )/\kappa _-$$  <math> <mrow> <mo>-</mo> <mtext>Im</mtext> <mrow> <mo>(</mo> <mi>ω</mi> <mo>)</mo> </mrow> <mo>/</mo> <msub> <mi>κ</mi> <mo>-</mo> </msub> </mrow> </math>   remains below 1/2. However, as the black holes approach extremality, the lowest mode’s  $$-\text {Im} (\omega )/\kappa _-$$  <math> <mrow> <mo>-</mo> <mtext>Im</mtext> <mrow> <mo>(</mo> <mi>ω</mi> <mo>)</mo> </mrow> <mo>/</mo> <msub> <mi>κ</mi> <mo>-</mo> </msub> </mrow> </math>   consistently exceeds 1/2, leading to a violation of SCC. Moreover, with a fixed cosmological constant, as the nonlinearity parameter  $$\alpha $$  <math> <mi>α</mi> </math>   increases, the interval of SCC violation under the charge extremality ratio narrows. Considering that  $$k = 1/2 + 1/\alpha $$  <math> <mrow> <mi>k</mi> <mo>=</mo> <mn>1</mn> <mo>/</mo> <mn>2</mn> <mo>+</mo> <mn>1</mn> <mo>/</mo> <mi>α</mi> </mrow> </math>   is inversely proportional to  $$\alpha $$  <math> <mi>α</mi> </math>  , our results indicate that increasing the order k of the non-linear electromagnetic field can effectively mitigate SCC violations.

China

Stability of Cauchy horizon in Einstein–Power–Maxwell–de Sitter black holes

We study dark matter scattering off  $$ ^4$$  <math> <mmultiscripts> <mrow></mrow> <mrow></mrow> <mn>4</mn> </mmultiscripts> </math>  He and other light nuclei using chiral effective field theory. We consider scalar DM interactions and include both one- and two-nucleon scattering processes. The DM interactions and nuclear wave functions are obtained from chiral effective field theory and we work up to fourth order in the chiral expansion for the latter to investigate the chiral convergence. The results for the scattering rates can be used to determine the sensitivity of planned experiments to detect relatively light dark matter particles using  $$ ^4$$  <math> <mmultiscripts> <mrow></mrow> <mrow></mrow> <mn>4</mn> </mmultiscripts> </math>  He. We find that next-to-leading-order scalar currents are smaller than expected from power counting for scattering off  $$ ^4$$  <math> <mmultiscripts> <mrow></mrow> <mrow></mrow> <mn>4</mn> </mmultiscripts> </math>  He confirming earlier work. However, the results for two-nucleon corrections exhibit a linear regulator dependence indicating potential problems in the applied power counting. We observe a linear correlation between the, in principle not observable, D-wave probability of various light nuclei and the scalar two-nucleon matrix elements, again pointing towards potentially missing contributions.

Netherlands

Dark matter scattering off  $$ ^{4}$$  <math> <mmultiscripts> <mrow></mrow> <mrow></mrow> <mn>4</mn> </mmultiscripts> </math>  He in chiral effective field theory

In order to explain the mass hierarchy and mixing pattern in the leptonic sector, we explore an extension of the Standard Model whose scalar sector includes one active and two inert doublets as well as some scalar singlets. The model includes a  $$S_3$$  <math> <msub> <mi>S</mi> <mn>3</mn> </msub> </math>   family symmetry supplemented by extra cyclic symmetries. As a consequence of our construction, a Dark Matter (DM) candidate is predicted and its properties are consistent with the observed cosmic abundances and the constraints imposed by direct and indirect detection experiments. The model allows Charged Lepton Flavor Violation (CLFV) processes like  $$\mu \rightarrow e\gamma $$  <math> <mrow> <mi>μ</mi> <mo>→</mo> <mi>e</mi> <mi>γ</mi> </mrow> </math>   and  $$\mu \rightarrow 3e$$  <math> <mrow> <mi>μ</mi> <mo>→</mo> <mn>3</mn> <mi>e</mi> </mrow> </math>  , but the predicted branching ratios align with experimental limits. Additionally, our analysis elucidates the generation of the active neutrino masses through a one-loop radiative seesaw mechanism matching the observed neutrino oscillation data. The model agrees with experimental data on Higgs Diphoton decay rates and on oblique parameters.

Chile

Phenomenology of an extended  $$1+2$$  <math> <mrow> <mn>1</mn> <mo>+</mo> <mn>2</mn> </mrow> </math>   Higgs doublet model with  $$S_3$$  <math> <msub> <mi>S</mi> <mn>3</mn> </msub> </math>   family symmetry

We briefly analyzed the equation of state and critical points of the quantum-corrected-AdS black hole and used the Melnikov method to study its thermal chaotic behavior in the extended phase space of flat, closed, and open universes. The results show that the black hole’s thermodynamic behavior is similar to that of the Van der Waals system. Although the critical ratios at the critical points in the three types of universes differ, they are all independent of the quantum correction parameter. Only an open universe can attain the critical ratio of  $$\frac{3}{8}$$  <math> <mfrac> <mn>3</mn> <mn>8</mn> </mfrac> </math>   corresponding to the Van der Waals system, while in the other two universes, the critical ratio is always greater than this value. For chaos, time perturbations will lead to chaotic behavior when their amplitude exceeds a critical value that depends on the quantum correction parameter and the radius of the dust sphere in the FRW model. Based on this, we found that the chaotic behavior of the black hole varies across different universes depending on the quantum correction parameter, but this parameter always makes chaos more likely. Using the value of the quantum correction parameter determined by Meissner, chaos is always more difficult to occur in an open universe compared to the other two types of universes. Which universe is most prone to chaos depends on the radius of the dust sphere. Finally, chaotic behavior is always present under spatial perturbations.

Thermal chaos of quantum-corrected-AdS black hole in the extended phase space

Our primary goal is to compare the analytic properties of hydrodynamic series with the stability and causality conditions applied to hydrodynamic modes. Analyticity, in this context, serves as a necessary condition for hydrodynamic series to behave as a univalent function. Stability and causality adhere to physical constraints, ensuring that hydrodynamic modes neither exhibit exponential growth nor travel faster than the speed of light. Through an examination of various hydrodynamic models, such as the Müller–Israel–Stewart (MIS) and the first-order hydro models like the BDNK (Bemfica–Disconzi–Noronha–Kovtun) model, we observe no new restrictions stemming from the univalence limits in the shear channels. However, local univalence is maintained in the sound channel of these models despite the global divergence of the hydrodynamic series. Notably, differences in the sound equations between the MIS and BDNK models lead to distinct limits. The MIS model’s sound mode remains univalent at high momenta within a specific transport range. Conversely, in the BDNK model, the univalence of the sound mode extends to intermediate momenta across all stable and causal regions. Generally, the convergence radius is independent of univalence, and the given dispersion relation predominantly influences their correlation. For second-order frequency dispersions, the relationship is precise; i.e., within the convergence radius, the hydro series demonstrates univalence. However, with higher-order dispersions, the hydro series is locally univalent within certain transport regions, which may fall within or outside the stable and causal zones.

Iran

Local univalence versus stability and causality in hydrodynamic models

In recent times, the study of the Casimir effect in quantum field theory has garnered increasing attention because of its potential to be an ideal source of exotic matter needed for stabilizing traversable wormholes. It has been confirmed through experimental evidence that this phenomenon involves fluctuations in the vacuum field, leading to a negative energy density. Motivated by the above, we have investigated Casimir wormholes with corrections from the Generalized Uncertainty Principle (GUP) within the framework of matter-coupled teleparallel gravity. Our analysis includes three well-known GUP models: the Kempf, Mangano, and Mann (KMM) model, the Detournay, Gabriel, and Spindel (DGS) model, and a third model called Model II. For a broader analysis, we have considered two well-known model functions for the teleparallel theory: a linear  $$f(T,\mathcal {T})=\alpha T+\beta \mathcal {T}$$  <math> <mrow> <mi>f</mi> <mo>(</mo> <mi>T</mi> <mo>,</mo> <mi>T</mi> <mo>)</mo> <mo>=</mo> <mi>α</mi> <mi>T</mi> <mo>+</mo> <mi>β</mi> <mi>T</mi> </mrow> </math>   and a quadratic model  $$f(T,\mathcal {T})=\eta T^2+\chi \mathcal {T}$$  <math> <mrow> <mi>f</mi> <mrow> <mo>(</mo> <mi>T</mi> <mo>,</mo> <mi>T</mi> <mo>)</mo> </mrow> <mo>=</mo> <mi>η</mi> <msup> <mi>T</mi> <mn>2</mn> </msup> <mo>+</mo> <mi>χ</mi> <mi>T</mi> </mrow> </math>  . The shape function solutions corresponding to both models are examined in the absence of tidal forces in spacetime. We also demonstrate the crucial role played by the parameters of the  $$f(T,\mathcal {T})$$  <math> <mrow> <mi>f</mi> <mo>(</mo> <mi>T</mi> <mo>,</mo> <mi>T</mi> <mo>)</mo> </mrow> </math>   models in the violation of the energy conditions. With the increasing interest in detecting gravitational waves from astrophysical objects, we have thoroughly discussed the perturbation of the wormhole solutions in the scalar, electromagnetic, axial gravitational, and Dirac field backgrounds. We employ the 3rd order WKB expansion to find the complex frequencies associated with the quasinormal modes of energy dissipation. Additionally, we also calculate the active mass and total gravitational energy for the wormhole geometry. The amount of exotic matter involved in sustaining these wormholes is also found in this paper. Furthermore, the physical stability of such Casimir wormholes is examined using the Tolman–Oppenheimer–Volkoff equation.