Journal of Astrophysics and Astronomy最新文献_第7页

Rationalization of the restricted six-body problem’s chaotic behavior 受限六体问题混沌行为的合理化

IF 1.6 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2026-03-21 DOI: 10.1007/s12036-026-10137-4

SANJEEV KUMAR, A K AWASTHI

{"title":"Rationalization of the restricted six-body problem’s chaotic behavior","authors":"SANJEEV KUMAR, A K AWASTHI","doi":"10.1007/s12036-026-10137-4","DOIUrl":"10.1007/s12036-026-10137-4","url":null,"abstract":"<div><p>The six-body problem, a specific instance of the general N-body problem in celestial mechanics, presents one of the most complex and chaotic dynamics in the study of gravitational systems. Rooted in Newton’s law of universal gravitation, the problem extends to a system of 36 coupled first-order differential equations requiring intricate initial conditions for solutions. Despite advances in understanding smaller systems, such as the three-body problem and its association with chaos (notably established by Poincaré), the restricted six-body problem remains a frontier of computational and theoretical challenge. This paper investigates the chaotic behavior of the six-body problem through rigorous analysis of its equations of motion, Lyapunov exponents, and energy dynamics. Numerical simulations are employed to visualize the intricate chaos and uncover the underlying patterns, while advanced techniques such as ergodic theory, probability distributions, and OGY control methods are applied to rationalize and mitigate the chaotic nature of the system. Symmetry reductions are explored as a means to simplify the complexity, making the problem more tractable without losing its core dynamics. The study also provides a detailed exploration of libration points and their stability, contributing to the ongoing discourse on chaotic behavior in multi-body gravitational interactions. The results highlight the interplay between chaos and order, offering new insights into the rationalization of complex dynamical systems. Numerical experiments, visualizations, and theoretical discussions together illuminate potential pathways to control and predict such intricate systems, advancing our understanding of chaotic dynamics in celestial mechanics.</p></div>","PeriodicalId":610,"journal":{"name":"Journal of Astrophysics and Astronomy","volume":"47 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147560598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

Relativistic charged anisotropic stars under Chaplygin equation of state with embedding constraints 具有嵌入约束的Chaplygin状态方程下的相对论荷电各向异性恒星

IF 1.6 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2026-03-21 DOI: 10.1007/s12036-026-10133-8

Alberto K. Mathias, Jonas W. Jape

引用次数: 0

Global response of low and mid-latitude ionosphere to the severe geomagnetic storm of April 2023 低中纬度电离层对2023年4月强地磁风暴的全球响应

IF 1.6 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2026-03-11 DOI: 10.1007/s12036-026-10135-6

Viswanathan Lakshmi Narayanan

{"title":"Global response of low and mid-latitude ionosphere to the severe geomagnetic storm of April 2023","authors":"Viswanathan Lakshmi Narayanan","doi":"10.1007/s12036-026-10135-6","DOIUrl":"10.1007/s12036-026-10135-6","url":null,"abstract":"<div><p>The response of topside ionosphere over low and midlatitudes to the severe geomagnetic storm of 23–24 April 2023 are studied using in-situ plasma measurements made by the Swarm satellite constellation at altitudes of 470 and 510 km. The local time coverage during the period was on dawn and dusk sectors. The geomagnetic storm is a two-step storm reaching a minimum SYM-H index magnitude of −233 nT. Observations reveal positive ionospheric storm with plasma density enhancements during sunlit periods of the main phase of the geomagnetic storm. This enhancement is significant over the Southern hemisphere. A clear increase in the equatorial electric field due to prompt penetration field is inferred through the increased separation of EIA crests and plasma density enhancements. This event showcased a longlasting prompt penetration electric field covering both the main phases. Interestingly, during the temporary recovery phase between the first and second main phases, the ionospheric observations are similar to those in the main phases with no indication of an overshielding electric field. During predawn hours of temporary recovery phase, a negative ionospheric storm is observed only over low latitudes. During the recovery phase, disturbed dynamo effects are also observed. However, for the first five hours in the early recovery phase, the effects were still similar to that of main phase. While the ring current recovery indicated by SYM-H indices took more than 36 hours, the disturbance dynamo effects were seen in the ionosphere only for about 11 hours, and the ionosphere was behaving similar to the quiet periods after 16 hours of start of the recovery phase. The observations are explained by means of undershielding prompt penetration electric fields during the main phases and development of disturbed dynamo effect well into the recovery phase.\u0000</p></div>","PeriodicalId":610,"journal":{"name":"Journal of Astrophysics and Astronomy","volume":"47 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147441047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

A phenomenon of "asymptotic freedom" arises in Schwarzschild spacetime based on a special Lorentz violation model 基于一种特殊的洛伦兹违背模型，在史瓦西时空中出现了“渐近自由”现象

IF 1.6 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2026-03-07 DOI: 10.1007/s12036-026-10130-x

Jinwen Hu

引用次数: 0

Study on the temperature and entropy of KSK black holes KSK黑洞的温度和熵的研究

IF 1.6 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2026-02-25 DOI: 10.1007/s12036-026-10128-5

Huiying Wang, Menquan Liu

引用次数: 0

Investigation of periodic resonant orbits in the binary stellar systems 双星系统周期共振轨道的研究

IF 1.6 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2026-02-24 DOI: 10.1007/s12036-026-10129-4

Prashant Kumar, Dinesh Kumar, Akhileshwar Singh

{"title":"Investigation of periodic resonant orbits in the binary stellar systems","authors":"Prashant Kumar, Dinesh Kumar, Akhileshwar Singh","doi":"10.1007/s12036-026-10129-4","DOIUrl":"10.1007/s12036-026-10129-4","url":null,"abstract":"<div><p>Resonant periodic orbits are investigated in binary star systems with three bodies. Kepler-34, Kepler-35, Kepler-413, and Kepler-16 are chosËen and surface of sections of Poincaré (SSP) is utilized in this study. As the mass ratio decreases, the amplitude of the stability regions decreases and for smaller mass ratios, the structure of the phase plane differs significantly from that observed at higher mass ratios. Using the technique of SSP, locations of the resonant periodic orbits 9:7, 7:5, 3:2, 4:3, 5:3, 1:1, and 2:3 are explored. The starting point and path of the periodic orbits around the primary are analysed for different radiation force and Jacobi constant values. The radiation pressure of the bigger primary has no effect on the resonance order. The position of the periodic orbits, however, fluctuates and significant variations in the eccentricity are observed. The inclusion of the radiation force causes the periodic orbits of resonance 9:7, 7:5, 3:2, 4:3, 5:3, 1:1 and 2:3 around the larger primary to shift in the direction of the smaller primary. Periodic orbits are used to investigate tiny binary system bodies, such comets and asteroids, whose motion can be strongly influenced by solar radiation pressure.</p></div>","PeriodicalId":610,"journal":{"name":"Journal of Astrophysics and Astronomy","volume":"47 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147341577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

A comparative study of the geoeffectiveness of interplanetary features of DH-HCMEs and non-DH-HCMEs dh - hcme与非dh - hcme行星际特征地球有效性比较研究

IF 1.6 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2026-02-23 DOI: 10.1007/s12036-026-10132-9

Suman Garia, Lalit Garia

{"title":"A comparative study of the geoeffectiveness of interplanetary features of DH-HCMEs and non-DH-HCMEs","authors":"Suman Garia, Lalit Garia","doi":"10.1007/s12036-026-10132-9","DOIUrl":"10.1007/s12036-026-10132-9","url":null,"abstract":"<div><p>Radiation and high-energy particles linked to solar activity around sunspots, including solar flares and coronal mass ejections (CMEs), can be harmful to living organisms. Major geomagnetic storms (GSs) might weaken the geomagnetic field, allowing energetic particles to penetrate the Earth's magnetosphere. Thus, analyzing corresponding solar flares or CMEs provides geoeffective parameters that help in predicting GSs. The purpose of the present study is to compare the geoeffectiveness of interplanetary features associated with DH type II burst-linked Halo CMEs (DH-HCMEs) and those not associated with DH type II bursts (Non-DH-HCMEs). In this study, it was observed that plasma flow pressure (FP) and flow speed (FS) attain their maximum values either before or during the main phase of the GS for both DH-HCMEs and Non-DH-HCMEs. We observed that the maximum values of FS and FP during solar cycle 23 (SC23), solar cycle 24 (SC24), and solar cycle 25 (SC25) are directly correlated with the lowest value of the Dst index for both DH-HCMEs and Non-DH-HCMEs. The analysis further showed that the Dst index decreases more significantly with increasing maximum solar wind speed (Vmax) of the disturbance across all three solar cycles, for moderate, intense, and severe GSs. Additionally, the Vmax associated with DH-HCMEs was consistently higher than that of Non-DH-HCMEs. We found that storm intensity is primarily driven by FP, with higher FP resulting in a more negative Dst index. Different FS regimes were also observed to have an impact on the value of the Dst index. In particular, during DH-HCME events in 2001 and 2005, we noted that when the Dst index rapidly dropped to its minimum—indicating a high rate of change of Dst index—FP did not decrease but instead remained relatively stable at a higher value. Since 2001 and 2005 were highly active years in SC23, the enhanced solar activity likely contributed to the occurrence of more energetic and faster Halo CMEs.</p></div>","PeriodicalId":610,"journal":{"name":"Journal of Astrophysics and Astronomy","volume":"47 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147341432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

Anisotropic compact star with Vaidya–Tikekar potential in f(Q) gravity 重力f(Q)下具有Vaidya-Tikekar势的各向异性致密星

IF 1.6 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2026-02-20 DOI: 10.1007/s12036-025-10119-y

M. AWAIS, M. AZAM

引用次数: 0

Seasonal asymmetry in vertical distribution of meteor decay time at two conjugate polar latitudes 两个共轭极纬地区流星衰减时间垂直分布的季节不对称性

IF 1.6 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2026-02-09 DOI: 10.1007/s12036-025-10126-z

K. Chenna Reddy

{"title":"Seasonal asymmetry in vertical distribution of meteor decay time at two conjugate polar latitudes","authors":"K. Chenna Reddy","doi":"10.1007/s12036-025-10126-z","DOIUrl":"10.1007/s12036-025-10126-z","url":null,"abstract":"<div><p>The meteor occurrence height and decay time height are strongly dependent on local atmospheric conditions in the mesosphere and lower thermosphere region. In this study, we comparatively examine the seasonal behaviour of vertical distribution of meteor occurrence height and decay time height at two identical radars of conjugate polar latitudes, Esrange (<span>(68^circ )</span>N) and Rothera (<span>(68^circ )</span>S). To understand the nature of meteor trail variations, the received signal power is categorised into two groups, weak and strong echoes, and their seasonal mean vertical profiles are constructed. It has been noticed that the meteor occurrence height shows a seasonal symmetry; however, the decay time vertical profiles show an asymmetric pattern at conjugate polar latitudes, particularly for strong echoes. Seasonally, there is about 1 km difference in the occurrence height and decay time height of weak and strong echoes. From the decay time vertical profiles, it has been noticed that the decay time turning altitude (i.e., inflection point) varies seasonally in the altitude range of 80–86 km for weak and strong echoes. The maximum turning altitude of about 85 km is observed in Northern winter at Esrange (<span>(68^circ )</span>N) and in Southern summer at Rothera (<span>(68^circ )</span>S); similarly, the minimum turning altitude of about 80 km is observed in Northern winter at Esrange (<span>(68^circ )</span>N) and in Southern summer at Rothera (<span>(68^circ )</span>S). The probable reasons for such behaviour of meteor trails at opposite polar latitudes are discussed.</p></div>","PeriodicalId":610,"journal":{"name":"Journal of Astrophysics and Astronomy","volume":"47 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147337670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

A concordant ‘freely coasting’ cosmology 一个和谐的“自由滑行”宇宙论

IF 1.6 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2026-02-09 DOI: 10.1007/s12036-025-10127-y

SAVITA GAHLAUT, PRANAV KUMAR, GEETANJALI SETHI, DAKSH LOHIYA

{"title":"A concordant ‘freely coasting’ cosmology","authors":"SAVITA GAHLAUT, PRANAV KUMAR, GEETANJALI SETHI, DAKSH LOHIYA","doi":"10.1007/s12036-025-10127-y","DOIUrl":"10.1007/s12036-025-10127-y","url":null,"abstract":"<div><p>A strictly linear evolution of the cosmological scale factor is surprisingly an excellent fit to a host of cosmological observations. Any model that can support such a coasting presents itself as a falsifiable model as far as classical cosmological tests are concerned. Such evolution is known to be comfortably concordant with the Hubble diagram as deduced from data of recent observations of low and high redshift objects, it passes constraints arising from the age and gravitational lensing statistics, and clears basic constraints on nucleosynthesis. Such an evolution exhibits distinguishable and verifiable features for the recombination era. This article discusses the concordance of such an evolution in relation to minimal requirements for large-scale structure formation and cosmic microwave background anisotropies along with the overall viability of such models. While these results should be of interest for a host of alternative gravity models that support a linear coasting, we conjecture that a linear evolution would emerge naturally either from General Relativity itself or from a General Relativistic theory of a non-minimally coupled scalar field theory.</p></div>","PeriodicalId":610,"journal":{"name":"Journal of Astrophysics and Astronomy","volume":"47 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147337712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0