Cadi Ayyad University
We derive a new Carleman estimate for a general backward stochastic parabolic equation with dynamic boundary conditions, incorporating weak divergence source terms in both the bulk and surface equations. This estimate is obtained through two main steps: first, by refining a known Carleman estimate for backward stochastic parabolic equations to explicitly account for the dependence of the parameters on the final control time TT; second, by applying a duality technique to address weak divergence source terms. As an application, we prove the null and approximate controllability of forward stochastic parabolic equations with dynamic boundary conditions, which involve both reaction and convection terms with bounded adapted coefficients, as well as general second-order parabolic operators. Additionally, we provide an explicit estimate for the null-controllability cost in terms of the final control time TT and the coefficients of the equation.
A study demonstrates that a multispectral foundation model, SpectralGPT, can be effectively adapted for hyperspectral image classification using parameter-efficient fine-tuning (PEFT) methods. The introduced KronA+ PEFT method consistently achieved high classification accuracy with minimal trainable parameters, often matching or exceeding dedicated hyperspectral models.
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We report the discovery of NGTS-11 c, a transiting warm Neptune (P12.8P \approx 12.8 d; Mp=1.20.2+0.3MNepM_{p} = 1.2^{+0.3}_{-0.2} M_{\mathrm{Nep}}; Rp=1.24±0.03RNepR_{p} = 1.24 \pm 0.03 R_{\mathrm{Nep}}), in an orbit interior to the previously reported transiting warm Saturn NGTS-11 b (P35.5P \approx 35.5 d). We also find evidence of a third outer companion orbiting the K-dwarf NGTS-11. We first detected transits of NGTS-11 c in TESS light curves and confirmed them with follow-up transits from NGTS and many other ground-based facilities. Radial-velocity monitoring with the HARPS and FEROS spectrographs revealed the mass of NGTS-11 c and provides evidence for a long-period companion (P>2300P > 2300 d; Mpsini>3.6MJupM_{p} \sin i > 3.6 M_{\mathrm{Jup}}). Taking into account the two additional bodies in our expanded datasets, we find that the mass of NGTS-11 b (Mp=0.63±0.09MSatM_{p} = 0.63 \pm 0.09 M_{\mathrm{Sat}}; Rp=0.97±0.02RSatR_{p} = 0.97 \pm 0.02 R_{\mathrm{Sat}}) is lower than previously reported (Mp=1.2±0.3MSatM_{p} = 1.2 \pm 0.3 M_{\mathrm{Sat}}). Given their near-circular and compact orbits, NGTS-11 c and b are unlikely to have reached their present locations via high-eccentricity migration. Instead, they probably either formed in situ or formed farther out and then underwent disk migration. A comparison of NGTS-11 with the eight other known systems hosting multiple well-characterized warm giants shows that it is most similar to Kepler-56. Finally, we find that the commonly used 10-day boundary between hot and warm Jupiters is empirically well supported.
Large Language Models (LLMs), especially their compact efficiency-oriented variants, remain susceptible to jailbreak attacks that can elicit harmful outputs despite extensive alignment efforts. Existing adversarial prompt generation techniques often rely on manual engineering or rudimentary obfuscation, producing low-quality or incoherent text that is easily flagged by perplexity-based filters. We present an automated red-teaming framework that evolves semantically meaningful and stealthy jailbreak prompts for aligned compact LLMs. The approach employs a multi-stage evolutionary search, where candidate prompts are iteratively refined using a population-based strategy augmented with temperature-controlled variability to balance exploration and coherence preservation. This enables the systematic discovery of prompts capable of bypassing alignment safeguards while maintaining natural language fluency. We evaluate our method on benchmarks in English (In-The-Wild Jailbreak Prompts on LLMs), and a newly curated Arabic one derived from In-The-Wild Jailbreak Prompts on LLMs and annotated by native Arabic linguists, enabling multilingual assessment.
CNRS logoCNRSUniversity of Amsterdam logoUniversity of AmsterdamNational Central UniversityNew York University logoNew York UniversityNikhefUniversity of MelbourneINFN logoINFNUniversity of WarsawJoint Institute for Nuclear ResearchUniversity of GranadaUniversity of GenoaSorbonne Université logoSorbonne UniversitéTechnical University of Munich logoTechnical University of MunichLeiden University logoLeiden UniversityUniversity of SheffieldUtrecht UniversityCadi Ayyad UniversityUniversity of JohannesburgINAFUnited Arab Emirates UniversityUniversity of South DakotaNCSR DemokritosLebedev Physical InstituteUniversity of ValenciaEberhard-Karls-Universität TübingenComenius UniversityGeorgian Technical UniversityUniversità di BariNational Centre for Nuclear ResearchWestern Sydney UniversityUniversitat Politécnica de ValénciaMohammed V UniversityInstitut de Physique des 2 Infinis de LyonUniversità di FirenzeUniversity of SalentoIFICUniversity of AthensUniversità degli Studi di Bari Aldo MoroPushchino Radio Astronomy ObservatoryLUPMLPC-CaenIFIN-HHChouaïb Doukkali UniversityInstitute of Experimental PhysicsTechnical University of KošiceUniversit di CataniaUniversité Sidi Mohamed Ben AbdellahRoyal Netherlands Institute for Sea ResearchUniversité Mohammed IerInstitut universitaire de technologie de Nantes* North–West UniversityUniversit degli Studi di FerraraUniversit de ParisUniversit Grenoble AlpesUniversit degli Studi di GenovaAix-Marseille Universit",Universit di SalernoUniversit Roma TreUniversit Paris CitUniversit La SapienzaUniversit de StrasbourgNantes UniversitUniversit di PadovaUniversit degli Studi di FirenzeUniversit degli Studi di Napoli Federico IIUniversit Di Bologna
Context: The detection of the highest energy neutrino observed to date by KM3NeT, with an estimated energy of 220 PeV, opens up new possibilities for the study and identification of the astrophysical sources responsible for a diffuse flux of such ultra-high-energy neutrinos, among which gamma-ray bursts are longstanding candidates. Aims: Based on the event KM3-230213A, we derive constraints on the baryon loading and density of the surrounding environment in models of blastwaves in long-duration gamma-ray bursts. Methods: We compute the diffuse flux from gamma-ray burst blastwaves, either expanding in a constant density interstellar medium or developing in a radially decreasing density of a wind-like environment surrounding the gamma-ray burst progenitor star, by taking into account the expected neutrino spectra and luminosity function. We use a Poisson likelihood method to constrain the blastwave model parameters by calculating the expected number of neutrino events within the 90% confidence level energy range of KM3-230213A and by using the joint exposure of KM3NeT/ARCA, IceCube and Pierre Auger. Results: We constrain the baryon loading to be {392,131,39,13}\leq \{392, 131, 39, 13\} at 90% confidence level, which is inversely proportional to a varying interstellar medium particle density of {1,3,10,30}\{1, 3, 10, 30\} cm3^{-3}. In the wind-like environment case, the baryon loading is {20,50,100}\leq \{20, 50, 100\} at 90% confidence level, which is proportional to the sixth power of a varying density parameter of {0.05,0.06,0.07}\{0.05, 0.06, 0.07\}.
A new method constructs generalized spherical barycentric coordinates by directly leveraging 3D barycentric coordinates of the origin within a specially formed polyhedron. These coordinates are proven to exhibit linear precision, non-negativity, the Lagrange property, and edge linearity, while offering increased robustness across diverse spherical point and polygon configurations.
Quantiles and expectiles are determined by different loss functions: asymmetric least absolute deviation for quantiles and asymmetric squared loss for expectiles. This distinction ensures that quantile regression methods are robust to outliers but somewhat less effective than expectile regression, especially for normally distributed data. However, expectile regression is vulnerable to lack of robustness, especially for heavy-tailed distributions. To address this trade-off between robustness and effectiveness, we propose a novel approach. By introducing a parameter γ\gamma that ranges between 0 and 1, we combine the aforementioned loss functions, resulting in a hybrid approach of quantiles and expectiles. This fusion leads to the estimation of a new type of location parameter family within the linear regression framework, termed Hybrid of Quantile and Expectile Regression (HQER). The asymptotic properties of the resulting estimaror are then established. Through simulation studies, we compare the asymptotic relative efficiency of the HQER estimator with its competitors, namely the quantile, expectile, and kkth power expectile regression estimators. Our results show that HQER outperforms its competitors in several simulation scenarios. In addition, we apply HQER to a real dataset to illustrate its practical utility.
The interstellar comet 3I/ATLAS is only the third interstellar object to be discovered. Pre-perihelion measurements provide a unique opportunity to study its activity and composition, which may alter as it is heated in the coming months. We provide an initial baseline from optical spectroscopic observations obtained only two days after discovery, using the MUSE instrument on the VLT on 2025 July 3, while 3I was at 4.47 au from the Sun and 3.46 au from the Earth. These observations confirm the cometary nature of 3I, and reveal a red coma with a spectral slope of (18±4)%/1000(18\pm4)\%/1000~Å, redder than most Solar System comets but similar to the surface colour of some Solar System Trans-Neptunian Objects or Centaurs. We searched for but did not detect gas emission from C2_2, NH2_2, CN, and [OI], which is consistent with volatile non-detections for Solar System comets at this heliocentric distance. At present, the coma appears entirely dusty. Future observations of 3I as it comes closer to the Sun will provide an invaluable opportunity to witness the evolution of its activity, study its composition, test predictions of interstellar object population models, and compare 3I to Solar System comets.
NASA's all-sky survey mission, the Transiting Exoplanet Survey Satellite (TESS), is specifically engineered to detect exoplanets that transit bright stars. Thus far, TESS has successfully identified approximately 400 transiting exoplanets, in addition to roughly 6000 candidate exoplanets pending confirmation. In this study, we present the results of our ongoing project, the Validation of Transiting Exoplanets using Statistical Tools (VaTEST). Our dedicated effort is focused on the confirmation and characterization of new exoplanets through the application of statistical validation tools. Through a combination of ground-based telescope data, high-resolution imaging, and the utilization of the statistical validation tool known as \texttt{TRICERATOPS}, we have successfully discovered eight potential super-Earths. These planets bear the designations: TOI-238b (1.610.10+0.09^{+0.09} _{-0.10} R_\oplus), TOI-771b (1.420.09+0.11^{+0.11} _{-0.09} R_\oplus), TOI-871b (1.660.11+0.11^{+0.11} _{-0.11} R_\oplus), TOI-1467b (1.830.15+0.16^{+0.16} _{-0.15} R_\oplus), TOI-1739b (1.690.08+0.10^{+0.10} _{-0.08} R_\oplus), TOI-2068b (1.820.15+0.16^{+0.16} _{-0.15} R_\oplus), TOI-4559b (1.420.11+0.13^{+0.13} _{-0.11} R_\oplus), and TOI-5799b (1.620.13+0.19^{+0.19} _{-0.13} R_\oplus). Among all these planets, six of them fall within the region known as 'keystone planets,' which makes them particularly interesting for study. Based on the location of TOI-771b and TOI-4559b below the radius valley we characterized them as likely super-Earths, though radial velocity mass measurements for these planets will provide more details about their characterization. It is noteworthy that planets within the size range investigated herein are absent from our own solar system, making their study crucial for gaining insights into the evolutionary stages between Earth and Neptune.
We establish transportation cost inequalities, with respect to the uniform and L2L_2-metric, on the path space of continuous functions, for laws of solutions of stochastic differential equations with reflections. We also consider the case of stochastic differential equations involving local times. Harnack inequalities for the associated semigroups are also established.
Planet formation models suggest that the formation of giant planets is significantly harder around low-mass stars, due to the scaling of protoplanetary disc masses with stellar mass. The discovery of giant planets orbiting such low-mass stars thus imposes strong constraints on giant planet formation processes. Here, we report the discovery of a transiting giant planet orbiting a 0.207±0.011M0.207 \pm 0.011 M_{\odot} star. The planet, TOI-6894 b, has a mass and radius of MP=0.168±0.022MJ(53.4±7.1M)M_P = 0.168 \pm 0.022 M_J (53.4 \pm 7.1 M_{\oplus}) and $R_P = 0.855 \pm 0.022 R_J,andlikelyincludes, and likely includes 12 \pm 2 M_{\oplus}$ of metals. The discovery of TOI-6894 b highlights the need for a better understanding of giant planet formation mechanisms and the protoplanetary disc environments in which they occur. The extremely deep transits (17% depth) make TOI-6894 b one of the most accessible exoplanetary giants for atmospheric characterisation observations, which will be key for fully interpreting the formation history of this remarkable system and for the study of atmospheric methane chemistry.
In this paper, we investigate the deterministic multidimensional Skorokhod problem with normal reflection in a family of time-dependent convex domains that are càdlàg with respect to the Hausdorff metric. We then show the existence and uniqueness of solutions to multidimensional McKean-Vlasov stochastic differential equations reflected in these time-dependent domains. Additionally, we derive stability properties with respect to the initial condition and the coefficients. Finally, we establish a propagation of chaos result.
This paper establishes existence, uniqueness, and an L^1-comparison principle for weak solutions of a PDE system modeling phase transition reaction-diffusion in congested crowd motion. We consider a general reaction term and mixed homogeneous (Dirichlet and Neumann) boundary conditions. This model is applicable to various problems, including multi-species diffusion-segregation and pedestrian dynamics with congestion. Furthermore, our analysis of the reaction term yields sufficient conditions combining the drift with the reaction that guarantee the absence of congestion, reducing the dynamics to a constrained linear reaction-transport equation.
In this paper, we examine the consistency of the Large Hadron Collider (LHC) data collected during Run 1 and 2 by the ATLAS and CMS experiments with the predictions of a 2-Higgs Doublet Model (2HDM) embedding Vector-Like Quarks (VLQs) for ppH,App \to H,A production and H,AγγH,A\to\gamma\gamma decay mechanisms, respectively, of (nearly) degenerate CP-even (HH) and CP-odd (AA) Higgs bosons. We show that a scenario containing one single VLQ with Electro-Magnetic (EM) charge 2/32/3 can explain the above ATLAS and CMS data for masses in the region 350 GeV mVLQ1.5\leq m_{\rm VLQ}\leq 1.5 TeV or so, depending on tanβ\tan\beta, and for several values of the mixing angle between the top quark (tt) and its VLQ counterpart (TT).We then perform a global fit onto the model by including all relevant experimental as well as theoretical constraints. The surviving samples of our analysis are discussed within 2σ\sigma of the LHC measurements. Additionally, we also comment on the recent anomalous result reported by CMS using Run 2 data on the associated Standard Model (SM) Higgs boson production with top quark pairs ppttˉhpp\to t\bar th with an observed significance of 3.3σ\sigma. Other than these specific examples, we also present a phenomenological analysis of the main features of the model, including the most promising TT decay channels.
High performance lead-free multiferroic composites are desired to replace the lead-based ceramics in multifunctional devices applications. Laminated compounds were prepared from ferroelectric and ferromagnetic materials. In this work, we present laminated ceramics compound by considering the ferromagnetic La0.5Ca0.5MnO3 (LCMO) and the ferroelectric BaTi0.8Sn0.2O3 (BTSO) in two different proportions. Compounds (1-x) LCMO-(x) BTSO with x=1 and 0 (pure materials) were synthesized by the sol gel method and x=0.7 and 0.5 (laminated) compounds were elaborated by welding appropriate mass ratios of each pure material by using the silver paste technique. Structural, dielectric, ferroelectric, microstructure and magnetic characterization were conducted on these samples. X-ray scattering results showed pure perovskite phases confirming the successful formation of both LCMO and BTSO. SEM images evidenced the laminated structure and good quality of the interfaces. The laminated composite materials have demonstrated a multiferroic behavior characterized by the ferroelectric and the ferromagnetic hysteresis loops. Furthermore, the enhancement of the dielectric constant in the laminated composite samples is mainly attributed to the Maxwell-Wagner polarization.
In this paper we investigate the shadow and energy emission rate of a charged AdS black hole in massive gravity. We develop a new prescription based on maximum frequencies of emission spectrum to probe the thermodynamics of black holes and get an accurate insight into its phase transition criticality. We establish a link between the thermodynamic behavior and the maximum emission frequency of the black hole for both the photons and massive bosonic modes. We show that the frequency maximizing the spectrum combined to the shadow radius can serve as a powerful physical tool to delve into the thermodynamics and phase structure of RN-AdS black holes in massive gravity.
CNRS logoCNRSUniversity of Amsterdam logoUniversity of AmsterdamCharles UniversityNikhefJoint Institute for Nuclear ResearchCSICUniversity of GranadaTechnical University of Munich logoTechnical University of MunichAustralian National University logoAustralian National UniversityLeiden University logoLeiden UniversityCEA logoCEAUniversity of BelgradeUtrecht UniversityCadi Ayyad UniversityUniversity of JohannesburgMohammed V University in RabatAix-Marseille UnivCzech Technical University in PragueUniversit`a di BolognaIMT AtlantiqueUniversit`a di CataniaUniversitat Polit`ecnica de Val`enciaUniversite de NantesUniversitat de ValenciaNational Centre for Nuclear ResearchINFN-Sezione di GenovaINFN-Sezione di BolognaINFN Sezione di RomaUniversit`a Degli Studi Di Napoli “Federico II”Universite de StrasbourgUniversit‘a di SalernoUniversit\`a degli Studi della Campania "Luigi Vanvitelli"INFN Laboratori Nazionali del SudTbilisi State UniversityUniversity Mohammed IUniversity of JaenUniversit´e de MontpellierWitwatersrand UniversityIstituto Nazionale di Fisica Nucleare, Sezione di NapoliUniversite de ParisRoyal Netherlands Institute for Sea Research (NIOZ)Universite de Haute AlsaceINFN (Sezione di Bari)IFIC (Instituto de F´ısica Corpuscular)Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH)Universit´e Paris Cit´eUniversit´e Paris Cˆote d’AzurFriedrich-Alexander-Universit¨at Erlangen-N¨rnbergIstituto Nazionale di Fisica Nucleare - Sezione di CataniaUniversità di Ferrara* National and Kapodistrian University of Athens* North–West UniversityUniversita’ ”La Sapienza”Université Paris-SaclayUniversită di GenovaSorbonne Université
The measurement of the flux of muons produced in cosmic ray air showers is essential for the study of primary cosmic rays. Such measurements are important in extensive air shower detectors to assess the energy spectrum and the chemical composition of the cosmic ray flux, complementary to the information provided by fluorescence detectors. Detailed simulations of the cosmic ray air showers are carried out, using codes such as CORSIKA, to estimate the muon flux at sea level. These simulations are based on the choice of hadronic interaction models, for which improvements have been implemented in the post-LHC era. In this work, a deficit in simulations that use state-of-the-art QCD models with respect to the measurement deep underwater with the KM3NeT neutrino detectors is reported. The KM3NeT/ARCA and KM3NeT/ORCA neutrino telescopes are sensitive to TeV muons originating mostly from primary cosmic rays with energies around 10 TeV. The predictions of state-of-the-art QCD models show that the deficit with respect to the data is constant in zenith angle; no dependency on the water overburden is observed. The observed deficit at a depth of several kilometres is compatible with the deficit seen in the comparison of the simulations and measurements at sea level.
This study focuses on precisely calculating analytical critical points for rotating regular AdS black holes, examining scenarios with and without external dark field contributions. Importantly, it represents the first attempt to compute critical points for this specific class of rotating black holes. Our primary focus is on investigating the impact resulting from variations in the charge of nonlinear electrodynamics on the critical phenomena of rotating regular AdS black holes, while also incorporating the influence of quintessence field contributions. The analytical investigation is concentrated on the horizon radius, employing two distinct approaches to simplify the complexity and length of the calculations. Furthermore, our examination extends to deciphering the intricate relationship between dark energy and critical phenomena. This involves visually portraying a range of critical behaviors and detailing a recent discovery regarding how the intensity of quintessence affects phase transitions. The shift in these transitions conform to either a concave or convex function, a characteristic dependent on the sign of quintessence intensity.
We suggest an explanation for and explore the consequences of the excess around 95 GeV in the di-photon and di-tau invariant mass distributions recently reported by the CMS collaboration at the Large Hadron Collider (LHC), together with the discrepancy that has long been observed at the Large Electron-Positron (LEP) collider in the bbˉb\bar b invariant mass. Interestingly, the most recent findings announced by the ATLAS collaboration do not contradict, or even support, these intriguing observations. Their search in the di-photon final state similarly reveals an excess of events within the same mass range, albeit with a bit lower significance, thereby corroborating and somewhat reinforcing the observations made by CMS. We demonstrate that the lightest CP-even Higgs boson in the general 2-Higgs Doublet Model (2HDM) Type-III can explain simultaneously the observed excesses at approximately 1.3 σ\sigma C.L. while satisfying up-to-date theoretical and experimental constraints. Moreover, the 2HDM Type-III predicts an excess in the ppttˉHSMpp\to t\bar t H_{\rm SM} production channel of the 125 GeV Higgs boson, HSMH_{\rm SM}. This effect is caused by a up to 12\% enhancement of the HSMttH_{\rm SM}tt Yukawa coupling in comparison to that predicted by the Standard Model. Such an effect can be tested at the High Luminosity LHC (HL-LHC), which can either discover or exclude the scenario we suggest. This unique characteristic of the 2HDM Type-III makes this scenario with the 95 GeV resonance very attractive for further theoretical and experimental investigations at the (HL-)LHC and future colliders.
GRB 221009A is the brightest Gamma-Ray Burst (GRB) detected in more than 50 years of study. In this paper, we present observations in the X-ray and optical domains after the GRB obtained by the GRANDMA Collaboration (which includes observations from more than 30 professional and amateur telescopes) and the Insight-HXMT Collaboration. We study the optical afterglow with empirical fitting from GRANDMA+HXMT data, augmented with data from the literature up to 60 days. We then model numerically, using a Bayesian approach, the GRANDMA and HXMT-LE afterglow observations, that we augment with Swift-XRT and additional optical/NIR observations reported in the literature. We find that the GRB afterglow, extinguished by a large dust column, is most likely behind a combination of a large Milky-Way dust column combined with moderate low-metallicity dust in the host galaxy. Using the GRANDMA+HXMT-LE+XRT dataset, we find that the simplest model, where the observed afterglow is produced by synchrotron radiation at the forward external shock during the deceleration of a top-hat relativistic jet by a uniform medium, fits the multi-wavelength observations only moderately well, with a tension between the observed temporal and spectral evolution. This tension is confirmed when using the extended dataset. We find that the consideration of a jet structure (Gaussian or power-law), the inclusion of synchrotron self-Compton emission, or the presence of an underlying supernova do not improve the predictions, showing that the modelling of GRB22109A will require going beyond the most standard GRB afterglow model. Placed in the global context of GRB optical afterglows, we find the afterglow of GRB 221009A is luminous but not extraordinarily so, highlighting that some aspects of this GRB do not deviate from the global known sample despite its extreme energetics and the peculiar afterglow evolution.
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