Asifa Ashraf, Allah Ditta, Abdelmalek Bouzenada, Muhammad Aslam, Phongpichit Channuie, Farruh Atamurotov, M. Y. Malik
{"title":"Particles dynamics with QPOs and thermodynamics features around a deformed anti-de sitter Schwarzschild black hole","authors":"Asifa Ashraf, Allah Ditta, Abdelmalek Bouzenada, Muhammad Aslam, Phongpichit Channuie, Farruh Atamurotov, M. Y. Malik","doi":"10.1140/epjc/s10052-025-14081-5","DOIUrl":"10.1140/epjc/s10052-025-14081-5","url":null,"abstract":"<div><p>We explore the dynamics of test particles around a deformed anti-de Sitter Schwarzschild black hole and analyze the influence of model parameters on particle motion. Using the effective potential technique, we examine the stability of equatorial circular orbits. We obtain the analytical expressions for the energy and angular momentum of test particles, along with the innermost stable circular orbits and the effective forces acting upon the test particles. We also probe the epicyclic oscillations of test particles close to the equatorial plane and further evaluate analytical expressions for radial, vertical, and orbital frequencies, including the periastron precession frequency. Additionally, we study the thermal characteristics of the black hole, investigating its Gibbs free energy, emission energy, and check the influence of other thermodynamic properties on the black hole model. Our findings indicate that the model parameters <i>M</i>, <span>( Lambda )</span>, <span>( alpha )</span> and <span>( beta )</span> considerably affect both the particle motion including epicyclic oscillations and the thermodynamic behavior.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14081-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143769872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Gravitational Faraday holonomy","authors":"Blake A. Parvin, Mark T. Lusk","doi":"10.1140/epjc/s10052-025-14086-0","DOIUrl":"10.1140/epjc/s10052-025-14086-0","url":null,"abstract":"<div><p>Closed optical trajectories in Kerr spacetime are engineered to exhibit a marked lack of symmetry. The eccentricity manifests as a holonomy in gravitational Faraday rotation that can be made arbitrarily large by radial translation of the common location of source and receiver. All trajectories are non-equatorial and include a passage through the equatorial plane at the radial turning point, where the trajectory and pseudo-magnetic field are well-aligned. This, combined with path asymmetry, results in a large gravitational Faraday holonomy that lends itself to experimental measurement. Trajectories that start further away from the singularity pass more closely to the ergosphere, thus transiting a more distorted region of spacetime with concomitant amplification of gravitational Coriolis force.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14086-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Detect anomalous quartic gauge couplings at muon colliders with quantum kernel k-means","authors":"Shuai Zhang, Ke-Xin Chen, Ji-Chong Yang","doi":"10.1140/epjc/s10052-025-14069-1","DOIUrl":"10.1140/epjc/s10052-025-14069-1","url":null,"abstract":"<div><p>In recent years, with the increasing luminosities of colliders, handling the growing amount of data has become a major challenge for future New Physics (NP) phenomenological research. In order to improve efficiency, machine learning algorithms have been introduced into the field of high-energy physics. As a machine learning algorithm, kernel k-means has been demonstrated to be useful for searching NP signals. It is well known that the kernel k-means algorithm can be carried out with the help of quantum computing, which suggests that quantum kernel k-means (QKKM) is also a potential tool for NP phenomenological studies in the future. This paper investigates how to search for NP signals using QKKM. Taking the <span>(mu ^+mu ^-rightarrow nu {bar{nu }}gamma gamma )</span> process at a muon collider as an example, the dimension-8 operators contributing to anomalous quartic gauge couplings (aQGCs) are studied. The expected coefficient constraints obtained using the QKKM of three different forms of quantum kernels, as well as the constraints obtained by the classical k-means algorithm are presented, and it can be shown that QKKM can help to find the signal of aQGCs. Comparing the classical k-means anomaly detection algorithm with QKKM, it is indicated that the QKKM is able to archive a better cut efficiency.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14069-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Some simple theories of gravity with propagating nonmetricity","authors":"Yusuke Mikura, Roberto Percacci","doi":"10.1140/epjc/s10052-025-14036-w","DOIUrl":"10.1140/epjc/s10052-025-14036-w","url":null,"abstract":"<div><p>We investigate symmetric metric-affine theories of gravity with a Lagrangian containing all operators of dimension up to four that are relevant to free propagation in flat space. Complementing recent work in the antisymmetric case, we derive the conditions for the existence of a single massive particle with good properties, in addition to the graviton.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14036-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Naveed Iqbal, S. Khan, Mohammad Alshammari, Wael W. Mohammed, M. Ilyas
{"title":"Nonmetricity-based hybrid self-gravitating compact stars with embedded class-one symmetry","authors":"Naveed Iqbal, S. Khan, Mohammad Alshammari, Wael W. Mohammed, M. Ilyas","doi":"10.1140/epjc/s10052-025-14102-3","DOIUrl":"10.1140/epjc/s10052-025-14102-3","url":null,"abstract":"<div><p>This work aims to explore the novel characteristics of a static hybrid transitional star with a spherical distribution of relativistic matter under the embedded class one metric framework. This theoretical stellar model is derived using the nonmetricity-inspired <span>(f(mathbb {Q}))</span> gravity, featuring a core-crust structure: a strange matter core embedded in a normal matter crust. Our model incorporates pressure anisotropy as an intrinsic characteristic of highly compact strange stars, a feature expected to arise in the super-dense regime. The equation of state, in its basic form, using the MIT bag model is employed to represent correlation between pressure and density in quark matter inside the star’s core. The development of this model involves selecting the temporal gravitational potential based on the Tolman–Kuchowicz ansatz, while the radial gravitational potential is determined using the Class One embedding formalism. We employed both analytical and graphical methods to assess the robustness and equilibrium of the presented stellar solution. We provide an in-depth description of the astrophysical features of the model and show that they fulfill regularity requirements. A key finding of this investigation is the absence of a core singularity within the anisotropic stellar formation. The solution matches the properties of the observed self-gravitating pulsar objects: SAX J1804.4-3658 (SS1), EXO1745-248, 4U1820-30, 4U1608-52, PSR J0740+6620, PSR J0030+0451, Cen X-4, and SAX J1804.4-3658 (SS2). \u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14102-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Reconciling fractional entropy and black hole entropy compositions","authors":"Manosh T. Manoharan, N. Shaji","doi":"10.1140/epjc/s10052-025-14107-y","DOIUrl":"10.1140/epjc/s10052-025-14107-y","url":null,"abstract":"<div><p>This study investigates the implications of adopting fractional entropy in the area law framework and demonstrates its natural alignment with an isothermal description of black hole composition. We discuss the Zeroth law compatibility of the fractional entropy and define an empirical temperature for the horizon. We highlight the distinction between the empirical and conventional Hawking temperatures associated with the black holes. Unlike the Hawking temperature, this empirical temperature appears universal, and its proximity to the Planck temperature suggests a possible quantum gravity origin. We also establish the connection between these temperatures. Furthermore, extending the conventional fractional parameter <i>q</i>, constrained between 0 and 1, we establish that any positive real number can bound <i>q</i> under the concavity condition, provided the log of micro-state dimensionality exceeds <span>(q-1)</span>. Specifically, for black holes, <span>(q = 2)</span>, necessitating micro-state dimensionality greater than <i>e</i>, thereby excluding the construction of black hole horizon states with two level bits or qubits. We also identify the connection between the validity of the second law and information fluctuation complexity. The second law requires that the variance of information content remain smaller than the area of the black hole horizon. This constraint naturally gives rise to a Boltzmann–Gibbs-like entropy for the black hole, which, in contrast to the canonical formulation, is associated with its mass rather than its area. Equilibrium distribution analysis uncovers multiple configurations, in which the one satisfying the prerequisites of probability distribution exhibits an exponent stretched form, revealing apparent deviation from the Boltzmann distribution.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14107-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Information conservation in de Sitter tunneling","authors":"Baoyu Tan","doi":"10.1140/epjc/s10052-025-14101-4","DOIUrl":"10.1140/epjc/s10052-025-14101-4","url":null,"abstract":"<div><p>In this paper, we consider the three most general cases of progressive de Sitter spacetime. The charged and magnetic particles tunnel into the magnetically charged Reissner–Nordström de Sitter black hole (the most general case of a static black hole), the Kerr–Newman–Kasuya de Sitter black hole (the most general case of a rotating black hole), and Bardeen de Sitter black hole (black hole without singularities). We use Parikh–Wilczek method to calculate the radiation spectra of these black holes respectively, and find that they deviate from the pure thermal spectra, satisfying the unitary principle. Our results support the conservation of information and are generally true for all asymptotic de Sitter space-times.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14101-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Myrzakulov, O. Donmez, M. Koussour, S. Muminov, D. Ostemir, J. Rayimbaev
{"title":"Energy conditions in (f(Q, L_m)) gravity","authors":"Y. Myrzakulov, O. Donmez, M. Koussour, S. Muminov, D. Ostemir, J. Rayimbaev","doi":"10.1140/epjc/s10052-025-14112-1","DOIUrl":"10.1140/epjc/s10052-025-14112-1","url":null,"abstract":"<div><p>We are experiencing a golden age of experimental cosmology, with exact and accurate observations being used to constrain various gravitational theories like never before. Alongside these advancements, energy conditions play a crucial theoretical role in evaluating and refining new proposals in gravitational physics. We investigate the energy conditions (WEC, NEC, DEC, and SEC) for two <span>(f(Q, L_m))</span> gravity models using the FLRW metric in a flat geometry. Model 1, <span>(f(Q, L_m) = -alpha Q + 2L_m + beta )</span>, features linear parameter dependence, satisfying most energy conditions while selectively violating the SEC to explain cosmic acceleration. The EoS parameter transitions between quintessence, a cosmological constant, and phantom energy, depending on <span>(alpha )</span> and <span>(beta )</span>. Model 2, <span>(f(Q, L_m) = -alpha Q + lambda (2L_m)^2 + beta )</span>, introduces nonlinearities, ensuring stronger SEC violations and capturing complex dynamics like dark energy transitions. While Model 1 excels in simplicity, Model 2’s robustness makes it ideal for accelerated expansion scenarios, highlighting the potential of <span>(f(Q, L_m))</span> gravity in explaining cosmic phenomena.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14112-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The bosonic string spectrum and the explicit states up to level 10 from the lightcone and the chaotic behavior of certain string amplitudes","authors":"Igor Pesando","doi":"10.1140/epjc/s10052-025-13955-y","DOIUrl":"10.1140/epjc/s10052-025-13955-y","url":null,"abstract":"<div><p>We compute the irreps and their multiplicities of bosonic string spectrum up to level 10 and we give explicitly the on shell top level lightcone states which make the irreps. For the irreps up to three indexes and all the totally antisymmetric ones we give the general recipe and the full irreps. It turns out that lightcone is quite efficient in building these low indexes irreps once the top level states are known. For scalars and vectors we compute the multiplicity up to level 22 and 19 respectively. The first scalar at odd level appears at level 11. For the bosonic string in non critical dimensions we argue that at level <i>N</i> there are always states transforming as tensors with <span>(sge frac{1}{2} N)</span> indices. Only in critical dimensions there are states with <span>(sle frac{1}{2} N)</span>. Looking at the explicit coefficients of the combinations needed to make the irreps from the lightcone states we trace the origin of the chaotic behavior of certain cubic amplitudes considered in literature to the extremely precise and sensitive mixtures of states. For example the vectors at level <span>(N=19)</span> are a linear combinations of states and when the coefficients are normalized to be integer some of them have more than 1200 figures.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13955-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
U. S. Qureshi, A. Gurrola, A. Flórez, C. Rodriguez
{"title":"Probing light scalars and vector-like quarks at the high-luminosity LHC","authors":"U. S. Qureshi, A. Gurrola, A. Flórez, C. Rodriguez","doi":"10.1140/epjc/s10052-025-14085-1","DOIUrl":"10.1140/epjc/s10052-025-14085-1","url":null,"abstract":"<div><p>A model based on a <span>(U(1)_{T^3_R})</span> extension of the Standard Model can address the mass hierarchy between generations of fermions, explain thermal dark matter abundance, and the muon <span>(g - 2)</span>, <span>(R_{(D)})</span>, and <span>(R_{(D^*)})</span> anomalies. The model contains a light scalar boson <span>(phi ')</span> and a heavy vector-like quark <span>(chi _textrm{u})</span> that can be probed at CERN’s large hadron collider (LHC). We perform a phenomenology study on the production of <span>(phi ')</span> and <span>({chi }_u)</span> particles from proton–proton <span>((textrm{pp}))</span> collisions at the LHC at <span>(sqrt{s}=13.6)</span> TeV, primarily through <span>(g{-g})</span> and <span>(t{-chi _textrm{u}})</span> fusion. We work under a simplified model approach and directly take the <span>(chi _textrm{u})</span> and <span>(phi ')</span> masses as free parameters. We perform a phenomenological analysis considering <span>(chi _textrm{u})</span> final states to b-quarks, muons, and neutrinos, and <span>(phi ')</span> decays to <span>(mu ^+mu ^-)</span>. A machine learning algorithm is used to maximize the signal sensitivity, considering an integrated luminosity of 3000 <span>(text {fb}^{-1})</span>. The proposed methodology can be a key mode for discovery over a large mass range, including low masses, traditionally considered difficult due to experimental constraints.\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14085-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}