Pub Date : 2025-12-17DOI: 10.1016/j.nuclphysb.2025.117271
Jihong Huang , Shun Zhou
In this paper, we continue to carry out the one-loop renormalization of the type-I seesaw model in the on-shell scheme. Different from the modified minimal-subtraction () scheme, such an investigation is mainly motivated by the fact that the on-shell scheme has been widely adopted in the renormalization of the standard electroweak theory and implemented for its precision tests. We first specify the physical parameters in the on-shell scheme, and then fix the corresponding counterterms through on-shell renormalization conditions. In the presence of massive Majorana neutrinos, we propose a practical method to determine gauge-independent counterterms for the lepton flavor mixing matrix. With the explicit counterterms in both the and on-shell schemes, we establish the matching relations of the electric charge, physical masses and flavor mixing matrix elements between these two schemes. Our results in the present and previous papers lay the foundation for precision calculations in the type-I seesaw model.
{"title":"One-loop renormalization of the type-I seesaw model in the on-shell scheme","authors":"Jihong Huang , Shun Zhou","doi":"10.1016/j.nuclphysb.2025.117271","DOIUrl":"10.1016/j.nuclphysb.2025.117271","url":null,"abstract":"<div><div>In this paper, we continue to carry out the one-loop renormalization of the type-I seesaw model in the on-shell scheme. Different from the modified minimal-subtraction (<span><math><mover><mrow><mrow><mi>M</mi></mrow><mi>S</mi></mrow><mo>‾</mo></mover></math></span>) scheme, such an investigation is mainly motivated by the fact that the on-shell scheme has been widely adopted in the renormalization of the standard electroweak theory and implemented for its precision tests. We first specify the physical parameters in the on-shell scheme, and then fix the corresponding counterterms through on-shell renormalization conditions. In the presence of massive Majorana neutrinos, we propose a practical method to determine gauge-independent counterterms for the lepton flavor mixing matrix. With the explicit counterterms in both the <span><math><mover><mrow><mrow><mi>M</mi></mrow><mi>S</mi></mrow><mo>‾</mo></mover></math></span> and on-shell schemes, we establish the matching relations of the electric charge, physical masses and flavor mixing matrix elements between these two schemes. Our results in the present and previous papers lay the foundation for precision calculations in the type-I seesaw model.</div></div>","PeriodicalId":54712,"journal":{"name":"Nuclear Physics B","volume":"1022 ","pages":"Article 117271"},"PeriodicalIF":2.8,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For theories with multiple couplings we construct simple expressions for the four-dimensional (or, in general, integer-dimensional) renormalization constants assuming that all divergences are logarithmical. These expressions allow relating all coefficients at ε-poles, logarithms, and (if exist) mixed terms to the coefficients of the renormalization group functions in any order of the perturbation theory for MS-like renormalization prescriptions. The result admits such a formulation in that ε-poles and ln Λ/μ enter on the same footing. For theories with two and three couplings we present explicit expressions for the pole/logarithm structure of renormalization constants in the lowest orders of the perturbation theory. They are verified by comparisons with the two-loop explicit calculation for SQCD+SQED and also with the previously known three-loop calculations for the φ4-theory with two couplings.
{"title":"Structure of renormalization constants for theories with multiple couplings in the MS-like subtraction schemes","authors":"G.V. Kovyrshin , N.P. Meshcheriakov , V.V. Shatalova , K.V. Stepanyantz","doi":"10.1016/j.nuclphysb.2025.117272","DOIUrl":"10.1016/j.nuclphysb.2025.117272","url":null,"abstract":"<div><div>For theories with multiple couplings we construct simple expressions for the four-dimensional (or, in general, integer-dimensional) renormalization constants assuming that all divergences are logarithmical. These expressions allow relating all coefficients at ε-poles, logarithms, and (if exist) mixed terms to the coefficients of the renormalization group functions in any order of the perturbation theory for MS-like renormalization prescriptions. The result admits such a formulation in that ε-poles and ln Λ/<em>μ</em> enter on the same footing. For theories with two and three couplings we present explicit expressions for the pole/logarithm structure of renormalization constants in the lowest orders of the perturbation theory. They are verified by comparisons with the two-loop explicit calculation for <span><math><mrow><mi>N</mi><mo>=</mo><mn>1</mn></mrow></math></span> SQCD+SQED and also with the previously known three-loop calculations for the φ<sup>4</sup>-theory with two couplings.</div></div>","PeriodicalId":54712,"journal":{"name":"Nuclear Physics B","volume":"1022 ","pages":"Article 117272"},"PeriodicalIF":2.8,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-16DOI: 10.1016/j.nuclphysb.2025.117249
Shamraiza Shabbir , M. Zeeshan Gul , M. Sharif , Nusrat Fatima
This article examines the late time cosmic evolution in the presence of bulk viscous fluid defined by a specific viscosity coefficient (ξ) as in the framework of gravity. In this context, represents the Ricci scalar, describes the trace of energy-momentum tensor, is Hubble parameter, ξ0, τ0 and n are positive constants. This study aims to explore the role of bulk viscosity in describing the dynamics of the early cosmos with a particular focus on the scenario of non-singular bounce. A particular form of the gravity model is chosen to assess how this modified gravity framework influences cosmic evolution. Moreover, we examine the conduct of various cosmological parameters to explore the presence of feasible cosmological bounce solutions. We also use linear perturbation to study the stability analysis. Our findings reveal the positive behavior of energy density, negative behavior of pressure as well as the violation of null energy condition and strong energy condition, which is required for the existence of viable bounce solutions. It is found that this gravitational theory effectively presents viable alternatives to the standard cosmological scenarios, hence providing valuable understanding of the gravitational force and the early universe.
{"title":"Singularity-free cosmic journey beyond the big bang: Insights from f(R,T) theory","authors":"Shamraiza Shabbir , M. Zeeshan Gul , M. Sharif , Nusrat Fatima","doi":"10.1016/j.nuclphysb.2025.117249","DOIUrl":"10.1016/j.nuclphysb.2025.117249","url":null,"abstract":"<div><div>This article examines the late time cosmic evolution in the presence of bulk viscous fluid defined by a specific viscosity coefficient (<em>ξ</em>) as <span><math><mrow><mi>ξ</mi><mo>=</mo><msub><mi>ξ</mi><mn>0</mn></msub><msup><mrow><mo>(</mo><mi>t</mi><mo>−</mo><msub><mi>τ</mi><mn>0</mn></msub><mo>)</mo></mrow><mrow><mo>−</mo><mn>2</mn><mi>n</mi></mrow></msup><mi>H</mi></mrow></math></span> in the framework of <span><math><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>,</mo><mi>T</mi><mo>)</mo></mrow></math></span> gravity. In this context, <span><math><mi>R</mi></math></span> represents the Ricci scalar, <span><math><mi>T</mi></math></span> describes the trace of energy-momentum tensor, <span><math><mi>H</mi></math></span> is Hubble parameter, <em>ξ</em><sub>0</sub>, <em>τ</em><sub>0</sub> and <em>n</em> are positive constants. This study aims to explore the role of bulk viscosity in describing the dynamics of the early cosmos with a particular focus on the scenario of non-singular bounce. A particular form of the <span><math><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>,</mo><mi>T</mi><mo>)</mo></mrow></math></span> gravity model is chosen to assess how this modified gravity framework influences cosmic evolution. Moreover, we examine the conduct of various cosmological parameters to explore the presence of feasible cosmological bounce solutions. We also use linear perturbation to study the stability analysis. Our findings reveal the positive behavior of energy density, negative behavior of pressure as well as the violation of null energy condition and strong energy condition, which is required for the existence of viable bounce solutions. It is found that this gravitational theory effectively presents viable alternatives to the standard cosmological scenarios, hence providing valuable understanding of the gravitational force and the early universe.</div></div>","PeriodicalId":54712,"journal":{"name":"Nuclear Physics B","volume":"1022 ","pages":"Article 117249"},"PeriodicalIF":2.8,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-15DOI: 10.1016/j.nuclphysb.2025.117265
Tomasz R. Taylor , Bin Zhu
We apply the S-matrix formalism developed in Part I to the interacting scalar theory in four-dimensional de Sitter spacetime. The amplitudes are computed in the angular momentum basis, appropriate to the representations of SO(1, 4) de Sitter symmetry group. We discuss the properties of wavefunctions in Bunch-Davies vacuum and derive a new integral representation for the Feynman propagator. We focus on deep infrared processes probing the large scale structure of spacetime, in particular on the processes that are normally forbidden by the energy-momentum conservation laws in flat spacetime. We find that there are no stable particles in self-interacting scalar field theory, but the decay rates are exponentially suppressed for particles with masses far above ℏ/cℓ, where ℓ is the de Sitter radius. We also show that the “all out” amplitudes describing multiparticle production from the vacuum are identically zero, hence Bunch-Davies vacuum is stable with respect to the matter interactions. We show that at the tree level, all scattering amplitudes are infrared finite, well-defined functions of quantum numbers. They have no kinematic singularities, except for the processes involving conformally coupled scalars.
我们将第一部分中发展的s矩阵形式理论应用于四维德西特时空中的相互作用标量理论。振幅在角动量基础上计算，适合于SO(1,4) de Sitter对称群的表示。讨论了Bunch-Davies真空中波函数的性质，推导了费曼传播子的一种新的积分表示。我们专注于探测大尺度时空结构的深红外过程，特别是在平坦时空中通常被能量-动量守恒定律所禁止的过程。我们发现在自相互作用标量场理论中不存在稳定粒子，但对于质量远高于h /c的粒子，衰减率被指数抑制，其中h为德西特半径。我们还证明了描述从真空中产生多粒子的“全部输出”振幅相同为零，因此班奇-戴维斯真空相对于物质相互作用是稳定的。我们证明，在树的水平上，所有的散射振幅是红外有限的，量子数的定义良好的函数。除了涉及共形耦合标量的过程外，它们没有运动奇点。
{"title":"Scattering of quantum particles in global de Sitter spacetime II: Scalars in deep infrared","authors":"Tomasz R. Taylor , Bin Zhu","doi":"10.1016/j.nuclphysb.2025.117265","DOIUrl":"10.1016/j.nuclphysb.2025.117265","url":null,"abstract":"<div><div>We apply the S-matrix formalism developed in Part I to the interacting scalar theory in four-dimensional de Sitter spacetime. The amplitudes are computed in the angular momentum basis, appropriate to the representations of <em>SO</em>(1, 4) de Sitter symmetry group. We discuss the properties of wavefunctions in Bunch-Davies vacuum and derive a new integral representation for the Feynman propagator. We focus on deep infrared processes probing the large scale structure of spacetime, in particular on the processes that are normally forbidden by the energy-momentum conservation laws in flat spacetime. We find that there are no stable particles in self-interacting scalar field theory, but the decay rates are exponentially suppressed for particles with masses far above ℏ/<em>c</em>ℓ, where ℓ is the de Sitter radius. We also show that the “all out” amplitudes describing multiparticle production from the vacuum are identically zero, hence Bunch-Davies vacuum is stable with respect to the matter interactions. We show that at the tree level, all scattering amplitudes are infrared finite, well-defined functions of quantum numbers. They have no kinematic singularities, except for the processes involving conformally coupled scalars.</div></div>","PeriodicalId":54712,"journal":{"name":"Nuclear Physics B","volume":"1022 ","pages":"Article 117265"},"PeriodicalIF":2.8,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigates the cosmological implications of the modified gravity model f(R, Σ, T), which extends general relativity by incorporating additional geometric and matter-energy contributions. The model is explored within a homogeneous and isotropic Friedmann-Robertson-Walker (FRW) universe, utilizing a deceleration parameterization q(z) to analyze the evolution of cosmic acceleration. The framework includes key physical parameters such as energy density ρ, isotropic pressure p, the equation of state parameter ω, and energy conditions. Observational constraints from Hubble parameter data is employed to determine best-fit values for H0, q0, and q1. Also, the study examines the dynamical evolution of dark energy through the plane, statefinder diagnostics {r, s}, and the Om(z) diagnostic, which offer a comparative analysis against the standard ΛCDM model. The results indicate that the present-day universe follows a quintessence-like trajectory. Notably, the model satisfies the Null and Dominant Energy Conditions, while violating the Strong Energy Condition, a necessary feature for explaining cosmic acceleration.
{"title":"f(R, Σ, T) gravity and cosmic acceleration: A comprehensive analysis of physical and kinematical parameters","authors":"S.H. Shekh , Anil Kumar Yadav , Anirudh Pradhan , Nafis Ahmad","doi":"10.1016/j.nuclphysb.2025.117245","DOIUrl":"10.1016/j.nuclphysb.2025.117245","url":null,"abstract":"<div><div>This study investigates the cosmological implications of the modified gravity model <em>f</em>(<em>R</em>, Σ, <em>T</em>), which extends general relativity by incorporating additional geometric and matter-energy contributions. The model is explored within a homogeneous and isotropic Friedmann-Robertson-Walker (FRW) universe, utilizing a deceleration parameterization <em>q</em>(<em>z</em>) to analyze the evolution of cosmic acceleration. The framework includes key physical parameters such as energy density <em>ρ</em>, isotropic pressure <em>p</em>, the equation of state parameter <em>ω</em>, and energy conditions. Observational constraints from Hubble parameter data is employed to determine best-fit values for <em>H</em><sub>0</sub>, <em>q</em><sub>0</sub>, and <em>q</em><sub>1</sub>. Also, the study examines the dynamical evolution of dark energy through the <span><math><mrow><mo>(</mo><mi>ω</mi><mo>−</mo><msup><mi>ω</mi><mo>′</mo></msup><mo>)</mo></mrow></math></span> plane, statefinder diagnostics {<em>r, s</em>}, and the <em>O<sub>m</sub></em>(<em>z</em>) diagnostic, which offer a comparative analysis against the standard ΛCDM model. The results indicate that the present-day universe follows a quintessence-like trajectory. Notably, the model satisfies the Null and Dominant Energy Conditions, while violating the Strong Energy Condition, a necessary feature for explaining cosmic acceleration.</div></div>","PeriodicalId":54712,"journal":{"name":"Nuclear Physics B","volume":"1022 ","pages":"Article 117245"},"PeriodicalIF":2.8,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work investigates a single-field inflationary model - a specific class of K-essence models - in which a coupling term exists between the canonical Lagrangian and the potential. This coupling term influences key inflationary parameters such as the power spectral index, the tensor-to-scalar ratio, the Hubble parameter, the equation of state parameter, and the slow-roll parameter. By solving the equations both numerically and analytically, we explore how this modification affects inflationary dynamics. Our results indicate that the coupling term, α, reduces inflationary parameters such as the tensor-to-scalar ratio, r, and improves the consistency with observational constraints from Planck and BICEP / Keck at confidence levels 68 % and 95 %. These findings show that the studied model provides a promising alternative for describing early universe dynamics while aligning with recent cosmological observations.
{"title":"Single-field inflation with K-essence model: Predictions, constraints, and theoretical viewpoints","authors":"Fereshteh Felegary , Thammarong Eadkhong , Farruh Atamurotov , Phongpichit Channuie","doi":"10.1016/j.nuclphysb.2025.117248","DOIUrl":"10.1016/j.nuclphysb.2025.117248","url":null,"abstract":"<div><div>This work investigates a single-field inflationary model - a specific class of K-essence models - in which a coupling term exists between the canonical Lagrangian and the potential. This coupling term influences key inflationary parameters such as the power spectral index, the tensor-to-scalar ratio, the Hubble parameter, the equation of state parameter, and the slow-roll parameter. By solving the equations both numerically and analytically, we explore how this modification affects inflationary dynamics. Our results indicate that the coupling term, <em>α</em>, reduces inflationary parameters such as the tensor-to-scalar ratio, <em>r</em>, and improves the consistency with observational constraints from Planck and BICEP / Keck at confidence levels 68 % and 95 %. These findings show that the studied model provides a promising alternative for describing early universe dynamics while aligning with recent cosmological observations.</div></div>","PeriodicalId":54712,"journal":{"name":"Nuclear Physics B","volume":"1022 ","pages":"Article 117248"},"PeriodicalIF":2.8,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-14DOI: 10.1016/j.nuclphysb.2025.117261
Jinzhou Liu, Denghui Li, Zhaowen Yan
We construct vertex operator realizations of the π-type dual Grothendieck universal characters with partitions and . Furthermore, these three types of dual Grothendieck universal characters are extended to their multiparameter versions. By establishing linear transformations of the vertex operator representations for three types of dual Grothendieck universal characters, we present their generating functions, explicit combinatorial formulas, and stability property.
{"title":"Three types of dual Grothendieck universal characters and integrable systems","authors":"Jinzhou Liu, Denghui Li, Zhaowen Yan","doi":"10.1016/j.nuclphysb.2025.117261","DOIUrl":"10.1016/j.nuclphysb.2025.117261","url":null,"abstract":"<div><div>We construct vertex operator realizations of the <em>π</em>-type dual Grothendieck universal characters with partitions <span><math><mrow><mi>π</mi><mo>=</mo><mo>(</mo><mn>3</mn><mo>)</mo><mo>,</mo><mi>π</mi><mo>=</mo><mo>(</mo><mn>2</mn><mo>,</mo><mn>1</mn><mo>)</mo></mrow></math></span> and <span><math><mrow><mi>π</mi><mo>=</mo><mo>(</mo><msup><mn>1</mn><mn>3</mn></msup><mo>)</mo></mrow></math></span>. Furthermore, these three types of dual Grothendieck universal characters are extended to their multiparameter versions. By establishing linear transformations of the vertex operator representations for three types of dual Grothendieck universal characters, we present their generating functions, explicit combinatorial formulas, and stability property.</div></div>","PeriodicalId":54712,"journal":{"name":"Nuclear Physics B","volume":"1022 ","pages":"Article 117261"},"PeriodicalIF":2.8,"publicationDate":"2025-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-13DOI: 10.1016/j.nuclphysb.2025.117258
H Aruna Kumara , Chaitra Chooda Chalavadi , V. Venkatesha
This study rigorously examines the influence of dark matter within the framework of gravity, with a particular emphasis on its critical role in facilitating traversable wormhole solutions. By employing anisotropic matter sources modeled through Bose-Einstein condensates and Einasto density profiles, we derive a novel class of wormhole solutions. The construction of the shape function relies on the density profile equation in conjunction with modified field equations, thereby establishing a theoretical foundation for these solutions. Careful selection of parameters ensures that the proposed solutions satisfy all requisite conditions for traversability. Moreover, we conduct a systematic evaluation of energy conditions across two distinct scenarios, further validating the physical viability of the models. The investigation also extends to analyzing anisotropic effects, exoticity parameters, and active gravitational mass. This work presents a comprehensive exploration of the physical feasibility and stability of wormhole structures within the context of modified gravity theories, offering significant contributions to our understanding of the interplay between dark matter and advanced gravitational phenomena.
{"title":"Investigating wormhole structures in f(R,Lm) gravity: Implications for dark matter","authors":"H Aruna Kumara , Chaitra Chooda Chalavadi , V. Venkatesha","doi":"10.1016/j.nuclphysb.2025.117258","DOIUrl":"10.1016/j.nuclphysb.2025.117258","url":null,"abstract":"<div><div>This study rigorously examines the influence of dark matter within the framework of <span><math><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>,</mo><msub><mi>L</mi><mi>m</mi></msub><mo>)</mo></mrow></math></span> gravity, with a particular emphasis on its critical role in facilitating traversable wormhole solutions. By employing anisotropic matter sources modeled through Bose-Einstein condensates and Einasto density profiles, we derive a novel class of wormhole solutions. The construction of the shape function relies on the density profile equation in conjunction with modified field equations, thereby establishing a theoretical foundation for these solutions. Careful selection of parameters ensures that the proposed solutions satisfy all requisite conditions for traversability. Moreover, we conduct a systematic evaluation of energy conditions across two distinct scenarios, further validating the physical viability of the models. The investigation also extends to analyzing anisotropic effects, exoticity parameters, and active gravitational mass. This work presents a comprehensive exploration of the physical feasibility and stability of wormhole structures within the context of <span><math><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>,</mo><msub><mi>L</mi><mi>m</mi></msub><mo>)</mo></mrow></math></span> modified gravity theories, offering significant contributions to our understanding of the interplay between dark matter and advanced gravitational phenomena.</div></div>","PeriodicalId":54712,"journal":{"name":"Nuclear Physics B","volume":"1022 ","pages":"Article 117258"},"PeriodicalIF":2.8,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-12DOI: 10.1016/j.nuclphysb.2025.117251
Rabia Saleem , Naila Aslam , Muhammad Israr Aslam
This study investigates the geometric configurations and dynamical behavior of thin-shell structures within the Hayward black hole (BH) framework. Using the Klein-Gordon (KG) equation and equation of motion, we analyze the evolution of thin-shells composed of massless and massive scalar fields, revealing distinct behaviors: monotonic collapse for massless fields and collapse to expansion transitions for massive fields. Stability analysis under radial perturbations shows that quintessence and dark energy equations of state yield stable configurations, while phantom energy remains unstable. The magnetic charge parameter g plays a crucial role, with larger values enhancing stability and reducing collapse tendencies. Optical properties are examined through shadow analysis, demonstrating that increasing g reduces the shadow radius, while finite distance observer effects cause systematic variations in apparent size and angular diameter. Application of the Gauss-Bonnet (GB) theorem reveals standard gravitational lensing behavior, with the weak deflection angle varying consistently with impact parameter u. A comparative analysis with Schwarzschild geometry shows distinctive strong-field deflection characteristics while maintaining weak-field consistency, highlighting the interplay between scalar fields, magnetic charge, and spacetime regularity in regular BH physics.
{"title":"Thin-shell configurations in Hayward profile: Dynamical stability, shadows, and light deflection angle","authors":"Rabia Saleem , Naila Aslam , Muhammad Israr Aslam","doi":"10.1016/j.nuclphysb.2025.117251","DOIUrl":"10.1016/j.nuclphysb.2025.117251","url":null,"abstract":"<div><div>This study investigates the geometric configurations and dynamical behavior of thin-shell structures within the Hayward black hole (BH) framework. Using the Klein-Gordon (KG) equation and equation of motion, we analyze the evolution of thin-shells composed of massless and massive scalar fields, revealing distinct behaviors: monotonic collapse for massless fields and collapse to expansion transitions for massive fields. Stability analysis under radial perturbations shows that quintessence and dark energy equations of state yield stable configurations, while phantom energy remains unstable. The magnetic charge parameter <em>g</em> plays a crucial role, with larger values enhancing stability and reducing collapse tendencies. Optical properties are examined through shadow analysis, demonstrating that increasing <em>g</em> reduces the shadow radius, while finite distance observer effects cause systematic variations in apparent size and angular diameter. Application of the Gauss-Bonnet (GB) theorem reveals standard gravitational lensing behavior, with the weak deflection angle varying consistently with impact parameter <em>u</em>. A comparative analysis with Schwarzschild geometry shows distinctive strong-field deflection characteristics while maintaining weak-field consistency, highlighting the interplay between scalar fields, magnetic charge, and spacetime regularity in regular BH physics.</div></div>","PeriodicalId":54712,"journal":{"name":"Nuclear Physics B","volume":"1022 ","pages":"Article 117251"},"PeriodicalIF":2.8,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-12DOI: 10.1016/j.nuclphysb.2025.117246
Ramón Herrera , Carlos Ríos
We investigate the reconstruction of standard and generalized Rastall gravity inflationary models, using the scalar spectral index and the Rastall parameter expressed as functions of the number of folds N. Within a general formalism, we derive the effective potential in terms of the relevant cosmological parameters and the Rastall parameter for these gravity frameworks. As a specific example, we analyze the attractor , first by considering constant values of the Rastall parameter to reconstruct the inflationary stage in standard Rastall gravity, and then by assuming a linear dependence on the number of folds N to reconstruct the inflationary model in generalized Rastall gravity. Thus, the reconstruction of the potential V(ϕ) is obtained for both standard and generalized Rastall gravity inflationary models. In both frameworks, we constrain key parameters of the reconstructed models during inflation using the latest observational data from Planck.
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