We investigate cosmic censorship in anti–de Sitter space in holographic models in which the ground state is described by a good singularity. These include supersymmetric truncations of string/M theory, for which a positive-energy theorem holds. At the boundary, our solutions describe a boost-invariant fluid in which the temperature decreases monotonically with time. On the gravity side, they correspond to black-brane spacetimes with a receding horizon. In classical gravity, curvature invariants at the horizon grow without bound. In the full theory this regime may or may not be reached. In some cases it is avoided by a phase transition to a regular geometry. In others it is reached but the boundary hydrodynamic evolution can be continued, provided the equation of state at parametrically small energies is known. Both cases require the inclusion of finite-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>N</mi></mrow></math> or finite-coupling effects.

Netherlands

Marc Aragonès Fontboté

Spain

David Mateos

Guillem Pérez Martín

CERN

Wilke van der Schee

Javier G. Subils

Cosmic Censorship in a Dual Collider

Following up on our earlier study [J. Bardhan et al., <a href="http://dx.doi.org/10.1103/PhysRevD.107.115001">Phys. Rev. D 107, 115001 (2023)</a>], we investigate the LHC prospects of pair-produced vectorlike <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>B</mi></mrow></math> quarks decaying exotically to a new gauge-singlet (pseudo)scalar field <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Φ</mi></math> and a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math> quark. After the electroweak symmetry breaking, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Φ</mi></math> decays predominantly to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>g</mi><mi>g</mi><mo>/</mo><mi>b</mi><mi>b</mi></math> final states, leading to a fully hadronic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>b</mi><mo>+</mo><mn>4</mn><mi>j</mi></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>6</mn><mi>b</mi></math> signature. Because of the large Standard Model background and the lack of leptonic handles, it is a difficult channel to probe. To overcome the challenge, we employ a hybrid deep learning model containing a graph neural network followed by a deep neural network. We estimate that such a state-of-the-art deep learning analysis pipeline can lead to a performance comparable to that in the semileptonic mode, taking the discovery (exclusion) reach up to about <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>M</mi></mrow><mrow><mi>B</mi></mrow></msub><mo>=</mo><mn>1.8</mn><mo stretchy="false">(</mo><mn>2.4</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math> at HL-LHC when <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> decays fully exotically, i.e., <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>BR</mi><mo stretchy="false">(</mo><mi>B</mi><mo stretchy="false">→</mo><mi>b</mi><mi mathvariant="normal">Φ</mi><mo stretchy="false">)</mo><mo>=</mo><mn>100</mn><mo>%</mo></mrow></math>.

India

Jai Bardhan

Tanumoy Mandal

Subhadip Mitra

Cyrin Neeraj

Mihir Rawat

Tagging fully hadronic exotic decays of the vectorlike <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>B</mi></mrow></math> quark using a graph neural network

We present a Bayesian holographic model constructed by integrating the equation of state and baryon number susceptibility at zero chemical potential from lattice quantum chromodynamics (QCD). The model incorporates error estimates derived from lattice data. With this model, we systematically investigate the thermodynamic properties of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2</mn><mo>+</mo><mn>1</mn></mrow></math>-flavor QCD system. Using Bayesian inference, we perform precise calibration of the model parameters and determined the critical end point (CEP) position under the maximum a posterior (MAP) estimation to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><msup><mi>T</mi><mi>c</mi></msup><mo>,</mo><msubsup><mi>μ</mi><mi>B</mi><mi>c</mi></msubsup><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>0.0859</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>,</mo><mn>0.742</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo stretchy="false">)</mo></math>. Additionally, we predict the CEP positions within 68% and 95% confidence levels, yielding <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><msup><mi>T</mi><mi>c</mi></msup><mo>,</mo><msubsup><mi>μ</mi><mi>B</mi><mi>c</mi></msubsup><msub><mo stretchy="false">)</mo><mrow><mn>68</mn><mo>%</mo></mrow></msub><mo>=</mo><mo stretchy="false">(</mo><mn>0.0820</mn><mo>−</mo><mn>0.0889</mn><mo>,</mo><mn>0.71</mn><mo>−</mo><mn>0.77</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><msup><mi>T</mi><mi>c</mi></msup><mo>,</mo><msubsup><mi>μ</mi><mi>B</mi><mi>c</mi></msubsup><msub><mo stretchy="false">)</mo><mrow><mn>95</mn><mo>%</mo></mrow></msub><mo>=</mo><mo stretchy="false">(</mo><mn>0.0816</mn><mo>−</mo><mn>0.0898</mn><mo>,</mo><mn>0.71</mn><mo>−</mo><mn>0.79</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, respectively. Moreover, to validate the reliability and predictive power of our approach, we conduct a comprehensive comparison between our predictions and potential CEP locations proposed by other theoretical models. This work not only establishes a novel Bayesian framework for holographic modeling but also provides valuable insights and theoretical support for exploring phase transitions in strongly interacting matter under extreme conditions.

China

Liqiang Zhu

Italy

Xun Chen

Germany

Kai Zhou

Hanzhong Zhang

Mei Huang

Bayesian inference of the critical end point in a (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2</mn><mo>+</mo><mn>1</mn></mrow></math>)-flavor system from holographic QCD

We apply the result of Kenneth and Klich [<a href="http://dx.doi.org/10.1103/PhysRevLett.97.160401">Phys. Rev. Lett. 97, 160401 (2006)</a>] to derive a theorem for two objects coupled to a Dirac field. We demonstrate that a sufficient condition for the Casimir interaction to be repulsive is for their geometric configuration to be odd under the same reflection operation considered in that work.

Argentina

Aitor Fernández

César D. Fosco

Guillermo Hansen

Sign of the Casimir force between two bodies coupled to a Dirac field

We study quantum gravity corrections to the no-boundary wavefunction describing a universe with spatial topology $\textit{S}$ × $\textit{S}$ . It has been suggested that quantum effects become increasingly important when the size of the circle is large relative to the sphere. In this paper, we confirm this claim by an explicit four-dimensional one-loop calculation of the gravitational path integral preparing such a state. In the process, we clarify some aspects of the gravitational path integral on complex spacetimes. These quantum corrections play a crucial role in ensuring that the norm of the wavefunction is naturally expressed in terms of a path integral over $\textit{S}$ × $\textit{S}$ at the classical level. We extend some of the analysis to more general spatial topologies, as well as to the inclusion of fermions.

United States

Gustavo Turiaci

Chih-Hung Wu

The wavefunction of a quantum $\textit{S}$

Dark matter (DM) genesis via Ultraviolet (UV) freeze-in embeds the seed of reheating temperature and dynamics in its relic density. Thus, discovery of such a DM candidate can possibly open the window for post-inflationary dynamics. However, there are several challenges in this exercise, as freezing-in DM possesses feeble interaction with the visible sector and therefore very low production cross-section at the collider. We show that mono-photon (and dilepton) signal at the ILC, arising from DM effective operators connected to the SM field strength tensors, can still warrant a signal discovery. We study both the scalar and fermionic DM production during reheating via UV freeze-in, when the inflaton oscillates at the bottom of a general monomial potential. Interestingly, we see, right DM abundance can be achieved only in the case of bosonic reheating scenario, satisfying bounds from big bang nucleosynthesis (BBN). This provides a unique correlation between collider signal and the post-inflationary dynamics of the Universe within single-field inflationary models.

Basabendu Barman

Subhaditya Bhattacharya

Sahabub Jahedi

Dipankar Pradhan

Abhik Sarkar

Lepton collider as a window to reheating via freezing in dark matter detection. Part II

We propose a novel quark mass matrix texture-pair with five free parameters, which fits the four quark mass ratios $\textit{m}$ /$\textit{m}$ , $\textit{m}$ /$\textit{m}$ , $\textit{m}$ /$\textit{m}$ , $\textit{m}$ /$\textit{m}$ , and the four CKM quark mixing observables. The matrices each have one texture zero, but the main innovation here is a “geometric” ansatz exploiting a pair of small complex expansion parameters, based on the geometry of the Unitarity Triangle. The fit to the observables is in good agreement with current experimental values renormalised to ~ 10 TeV, and offers decisive tests against future high-precision measurements of the unitarity triangle angles at the weak scale. We identify two novel symmetries of these mass matrices which explain the phenomenologically-successful relations $\textit{α}$ ≡ $\textit{ϕ}$ ≃ $$ \frac{\pi }{2} $$ and $\textit{β}$ ≡ $\textit{ϕ}$ ≃ $$ \frac{\pi }{8} $$ .

United Kingdom

P. Harrison

W. Scott

Unitarity triangle angles explained: a predictive new quark mass matrix texture

We explore the construction of diverse regular spacetimes (black holes and defects) in General Relativity using a generic parametrised density profile (the Dekel–Zhao profile), which includes, for specific parameter choices, various well-known examples usually studied in the context of dark matter halos. Our solutions, in the Schwarzschild gauge, include new regular black holes as well as non-singular solutions representing spacetime defects. For a sub-class of metrics, a TOV equation approach with a chosen equation of state works. The status of the energy conditions and the issue of geodesic completeness are explored in detail. We also provide possible Lagrangian density constructions for the matter energy–momentum tensors. Further, we study the shadow radius of the new regular black holes, and compare our findings with available observational results from the EHT collaboration. Finally, for the defect solution, we present a model for a stable star (a gravastar) by explicit use of the junction conditions and obtain relevant consequences highlighting its characteristic features.

Anjan Kar

Sayan Kar

Diverse regular spacetimes using a parametrised density profile

The Kerr-MOG black hole has recently attracted significant research attention and has been extensively applied in various fields. To accurately characterize the long-term dynamical evolution of charged particles around a Kerr-MOG black hole, it is essential to utilize numerical algorithms that are high-precision, stable, and capable of preserving the inherent physical structural properties. In this study, we employ explicit symplectic algorithms combined with the Hamiltonian splitting technique to numerically solve the equations of motion for charged particles. Initially, by decomposing the Hamiltonian into five integrable components, three distinct explicit symplectic algorithms ($\textit{S}$2, $\textit{S}$4, and $$PR{K_6}4)$$ are constructed. Numerical experiments reveal that the $$PR{K_6}4$$ algorithm achieves superior accuracy. Subsequently, we utilize Poincaré sections and the fast Lyapunov indicator (FLI) to investigate the dynamic evolution of the particle. Our numerical results demonstrate that the energy $\textit{E}$, angular momentum $\textit{L}$, magnetic field parameter $$\beta ,$$ black hole spin parameter $\textit{a}$, and MOG parameter $$\alpha $$ all significantly influence the particle’s motion. Specifically, the chaotic region expands with an increase in $\textit{E}$, $$\beta ,$$ or $$\alpha ,$$ but contracts with an increase in $\textit{a}$ or $\textit{L}$. Furthermore, when any two of these five parameters are varied simultaneously, it becomes evident that $\textit{a}$ and $\textit{L}$ predominantly dictate the system’s behavior. This study not only offers novel insights into the chaotic dynamics associated with Kerr-MOG black holes but also extends the application of symplectic algorithms in strong gravitational fields.

Zhenmeng Xu

Dazhu Ma

Wenfu Cao

Kai Li

Chaotic motion of charged test particles in a Kerr-MOG black hole with explicit symplectic algorithms

The inverse seesaw mechanism provides a concise scenario to produce tiny neutrino masses. Here we investigate the Majoron dark matter arising from the $$\mathrm{U(1)_L}$$ symmetry spontaneous breaking and matter–antimatter asymmetry in the framework of a high scale inverse seesaw mechanism. Due to the existence of a lepton-number-violating mass term, the Majoron gets its mass from radiative corrections. On the other hand, the Noether’s theorem indicates that the Majoron can obtain a non-zero initial velocity in the early universe, and then generates the relic abundance via kinetic misalignment mechanism. With the same initial Majoron velocity, the observed baryon asymmetry can also be explained through the so-called spontanous bayogenensis mechanism.

Ying-Quan Peng

Xiu-Fei Li

Cogenesis of Majoron dark matter and baryon asymmetry from a high scale inverse seesaw mechanism