Pub Date : 2024-06-29DOI: 10.3390/universe10070283
Mihailo Savić, Nikola Veselinović, Darije Maričić, Filip Šterc, Radomir Banjanac, Miloš Travar, Aleksandar Dragić
The study and better understanding of energetic transient phenomena caused by disturbances occurring on our Sun are of great importance, primarily due to the potential negative effects those events can have on Earth’s environment. Here, we present the continuation of our previous work on understanding the connection between disturbances in the flux of energetic particles induced in the near-Earth environment by the passage of interplanetary coronal mass ejections and related Forbush decrease events. The relationship between the shape of fluence spectra of energetic protons measured by the instruments on the SOHO/ERNE probe at Lagrange point L1, Forbush decrease parameters measured by the worldwide network of neutron monitors, and coronal mass ejection parameters measured in situ is investigated. Various parameters used to characterize transient phenomena and their impact on the heliosphere, provided by the WIND spacecraft, were utilized to improve the accuracy of the calculation of the associated energetic proton fluence. The single and double power laws with exponential rollover were used to model the fluence spectra, and their effectiveness was compared. Correlation analysis between exponents used to characterize the shape of fluence spectra and Forbush decrease parameters is presented, and the results obtained by the two models are discussed.
{"title":"Further Study of the Relationship between Transient Effects in Energetic Proton and Cosmic Ray Fluxes Induced by Coronal Mass Ejections","authors":"Mihailo Savić, Nikola Veselinović, Darije Maričić, Filip Šterc, Radomir Banjanac, Miloš Travar, Aleksandar Dragić","doi":"10.3390/universe10070283","DOIUrl":"https://doi.org/10.3390/universe10070283","url":null,"abstract":"The study and better understanding of energetic transient phenomena caused by disturbances occurring on our Sun are of great importance, primarily due to the potential negative effects those events can have on Earth’s environment. Here, we present the continuation of our previous work on understanding the connection between disturbances in the flux of energetic particles induced in the near-Earth environment by the passage of interplanetary coronal mass ejections and related Forbush decrease events. The relationship between the shape of fluence spectra of energetic protons measured by the instruments on the SOHO/ERNE probe at Lagrange point L1, Forbush decrease parameters measured by the worldwide network of neutron monitors, and coronal mass ejection parameters measured in situ is investigated. Various parameters used to characterize transient phenomena and their impact on the heliosphere, provided by the WIND spacecraft, were utilized to improve the accuracy of the calculation of the associated energetic proton fluence. The single and double power laws with exponential rollover were used to model the fluence spectra, and their effectiveness was compared. Correlation analysis between exponents used to characterize the shape of fluence spectra and Forbush decrease parameters is presented, and the results obtained by the two models are discussed.","PeriodicalId":48646,"journal":{"name":"Universe","volume":"56 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501920","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}
Pub Date : 2024-06-29DOI: 10.3390/universe10070284
Alessandro Di Marco, Emanuele Orazi, Gianfranco Pradisi
In this review, a pedagogical introduction to the concepts of slow-roll inflationary universe and number of e-folds is provided. In particular, the difference between the basic notion of e-folds (Ne) the total number of e-folds (NT) and the number of e-folds before the end of inflation (N) is outlined. The proper application of the number of e-folds before the end of inflation is discussed both as a time-like variable for the scalar field evolution and as a key parameter for computing inflationary predictions.
{"title":"Introduction to the Number of e-Folds in Slow-Roll Inflation","authors":"Alessandro Di Marco, Emanuele Orazi, Gianfranco Pradisi","doi":"10.3390/universe10070284","DOIUrl":"https://doi.org/10.3390/universe10070284","url":null,"abstract":"In this review, a pedagogical introduction to the concepts of slow-roll inflationary universe and number of e-folds is provided. In particular, the difference between the basic notion of e-folds (Ne) the total number of e-folds (NT) and the number of e-folds before the end of inflation (N) is outlined. The proper application of the number of e-folds before the end of inflation is discussed both as a time-like variable for the scalar field evolution and as a key parameter for computing inflationary predictions.","PeriodicalId":48646,"journal":{"name":"Universe","volume":"45 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501923","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}
Pub Date : 2024-06-29DOI: 10.3390/universe10070286
Yu Rong
We present an analysis of the ellipticities of galaxy groups, derived from the spatial distribution of member galaxies, revealing a notable incongruity between the observed local galaxy groups and their counterparts in the Lambda cold dark matter cosmology. Specifically, our investigation reveals a substantial disparity in the ellipticities of observed groups with masses 1013.0
{"title":"Galaxy Group Ellipticity Confirms a Younger Cosmos","authors":"Yu Rong","doi":"10.3390/universe10070286","DOIUrl":"https://doi.org/10.3390/universe10070286","url":null,"abstract":"We present an analysis of the ellipticities of galaxy groups, derived from the spatial distribution of member galaxies, revealing a notable incongruity between the observed local galaxy groups and their counterparts in the Lambda cold dark matter cosmology. Specifically, our investigation reveals a substantial disparity in the ellipticities of observed groups with masses 1013.0<Mh<1014.5M⊙h−1 exhibiting significantly higher ellipticities (at a confidence level of approximately 4σ) compared to their simulated counterparts. Notably, the consistent use of the same group finder for identifying galaxy groups in both observational and simulated datasets underscores the robustness of this result. This observation may imply a potential incongruence between the inferred age of the Universe from observations and the predictions of the model, which aligns with the younger Universe hypothesis suggested by the elevated fraction of observed satellite pairs with correlated line-of-sight relative velocities compared to simulations. Our findings significantly strengthen the plausibility of a younger age for our Universe.","PeriodicalId":48646,"journal":{"name":"Universe","volume":"79 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501922","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}
Pub Date : 2024-06-28DOI: 10.3390/universe10070281
Emanuel W. D. Dantas, Geová Alencar, Ilde Guedes, Milko Estrada
In this work, we utilize the dynamic invariant method to obtain a solution for the time-dependent Schrödinger equation, aiming to explore the quantum theory of a p-form gauge field propagating in D-dimensional de Sitter spacetimes. Thus, we present a generalization, through the use of p-form gauge fields, of the quantization procedure for the scalar, electromagnetic, and Kalb–Ramond fields, all of which have been previously studied in the literature. We present an exact solution for the p-form gauge field when D=2(p+1), and we highlight the connection of the p=4 case with the chiral N=2, D=10 superstring model. We could observe particle production for D≠2(p+1) because the solutions are time-dependent. Additionally, observers in an accelerated co-moving reference frame will also experience a thermal bath. This could have significance in the realm of extra-dimensional physics, and presents the intriguing prospect that precise observations of the Cosmic Microwave Background might confirm the presence of additional dimensions.
在这项工作中，我们利用动态不变量方法获得了随时间变化的薛定谔方程的解，旨在探索在 D 维德西特时空中传播的 p 形规量场的量子理论。因此，我们通过使用 p 形规量场，对标量场、电磁场和卡尔布-拉蒙德场的量子化过程进行了概括。我们提出了 D=2(p+1) 时 p 形规量场的精确解，并强调了 p=4 情况与手性 N=2, D=10 超弦模型的联系。我们可以观测到 D≠2(p+1)时的粒子产生，因为解是随时间变化的。此外，处于加速共动参照系中的观测者也会经历热浴。这可能在超维物理领域具有重要意义，并带来了一个有趣的前景：对宇宙微波背景的精确观测可能会证实额外维度的存在。
{"title":"Quantized p-Form Gauge Field in D-Dimensional de Sitter Spacetime","authors":"Emanuel W. D. Dantas, Geová Alencar, Ilde Guedes, Milko Estrada","doi":"10.3390/universe10070281","DOIUrl":"https://doi.org/10.3390/universe10070281","url":null,"abstract":"In this work, we utilize the dynamic invariant method to obtain a solution for the time-dependent Schrödinger equation, aiming to explore the quantum theory of a p-form gauge field propagating in D-dimensional de Sitter spacetimes. Thus, we present a generalization, through the use of p-form gauge fields, of the quantization procedure for the scalar, electromagnetic, and Kalb–Ramond fields, all of which have been previously studied in the literature. We present an exact solution for the p-form gauge field when D=2(p+1), and we highlight the connection of the p=4 case with the chiral N=2, D=10 superstring model. We could observe particle production for D≠2(p+1) because the solutions are time-dependent. Additionally, observers in an accelerated co-moving reference frame will also experience a thermal bath. This could have significance in the realm of extra-dimensional physics, and presents the intriguing prospect that precise observations of the Cosmic Microwave Background might confirm the presence of additional dimensions.","PeriodicalId":48646,"journal":{"name":"Universe","volume":"10 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501926","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}
Pub Date : 2024-06-28DOI: 10.3390/universe10070280
Jianxi Song, Yanli Li, Shi-Chen Xue, Hui Li, Xiaoyu Wang
We investigate the cos2ϕh azimuthal asymmetry contributed by the coupling of the Boer–Mulders function and the Collins function in K±- and Λ-hyperon-produced SIDIS process. The asymmetry is studied under the transverse-momentum-dependent (TMD) factorization framework at the leading order by considering the TMD evolution effects that utilize the parametrization for non-perturbative Sudakov form factors. The DGLAP evolution effects of the collinear counterpart of the Collins function of the final-state hadrons are considered by introducing the approximated evolution kernels. We utilize the available parametrization for the proton Boer–Mulders function and the Collins function of K±. For the Collins function of the Λ hyperon, the result of the diquark spectator model is adopted due to the absence of parametrization. The numerical results of the cos2ϕh azimuthal asymmetry are obtained in the kinematic regions of EIC and EicC. It can be shown that the asymmetry is much smaller than the Sivers asymmetry, which means that the convolution of the Boer–Mulders function and the Collins function may not be the main contributor to the cos2ϕh asymmetry. We emphasize the importance of future measurement of the cos2ϕh asymmetry to unravel different contributors.
{"title":"The cos 2ϕh Asymmetry in K± Mesons and the Λ-Hyperon-Produced SIDIS Process at Electron Ion Colliders","authors":"Jianxi Song, Yanli Li, Shi-Chen Xue, Hui Li, Xiaoyu Wang","doi":"10.3390/universe10070280","DOIUrl":"https://doi.org/10.3390/universe10070280","url":null,"abstract":"We investigate the cos2ϕh azimuthal asymmetry contributed by the coupling of the Boer–Mulders function and the Collins function in K±- and Λ-hyperon-produced SIDIS process. The asymmetry is studied under the transverse-momentum-dependent (TMD) factorization framework at the leading order by considering the TMD evolution effects that utilize the parametrization for non-perturbative Sudakov form factors. The DGLAP evolution effects of the collinear counterpart of the Collins function of the final-state hadrons are considered by introducing the approximated evolution kernels. We utilize the available parametrization for the proton Boer–Mulders function and the Collins function of K±. For the Collins function of the Λ hyperon, the result of the diquark spectator model is adopted due to the absence of parametrization. The numerical results of the cos2ϕh azimuthal asymmetry are obtained in the kinematic regions of EIC and EicC. It can be shown that the asymmetry is much smaller than the Sivers asymmetry, which means that the convolution of the Boer–Mulders function and the Collins function may not be the main contributor to the cos2ϕh asymmetry. We emphasize the importance of future measurement of the cos2ϕh asymmetry to unravel different contributors.","PeriodicalId":48646,"journal":{"name":"Universe","volume":"1 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501924","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}
Pub Date : 2024-06-28DOI: 10.3390/universe10070282
Minxuan Cai, Zhen Wan, Zhenyi Cai, Lulu Fan, Junxian Wang
In terms of the variable nature of normal active galaxy nuclei (AGN) and luminous quasars, a so-called flux variation gradient (FVG) method has been widely utilized to estimate the underlying non-variable host galaxy fluxes. The FVG method assumes an invariable AGN color, but this assumption has been questioned by the intrinsic color variation of quasars and local Seyfert galaxies. Here, using an up-to-date thermal fluctuation model to simulate multi-wavelength AGN variability, we theoretically demonstrate that the FVG method generally overestimates the host galaxy flux; that is, it is more significant for brighter AGN/quasars. Furthermore, we observationally confirm that the FVG method indeed overestimates the host galaxy flux by comparing it to that estimated through other independent methods. We thus caution that applying the FVG method should be performed carefully in the era of time-domain astronomy.
{"title":"The Host Galaxy Fluxes of Active Galaxy Nuclei Are Generally Overestimated by the Flux Variation Gradient Method","authors":"Minxuan Cai, Zhen Wan, Zhenyi Cai, Lulu Fan, Junxian Wang","doi":"10.3390/universe10070282","DOIUrl":"https://doi.org/10.3390/universe10070282","url":null,"abstract":"In terms of the variable nature of normal active galaxy nuclei (AGN) and luminous quasars, a so-called flux variation gradient (FVG) method has been widely utilized to estimate the underlying non-variable host galaxy fluxes. The FVG method assumes an invariable AGN color, but this assumption has been questioned by the intrinsic color variation of quasars and local Seyfert galaxies. Here, using an up-to-date thermal fluctuation model to simulate multi-wavelength AGN variability, we theoretically demonstrate that the FVG method generally overestimates the host galaxy flux; that is, it is more significant for brighter AGN/quasars. Furthermore, we observationally confirm that the FVG method indeed overestimates the host galaxy flux by comparing it to that estimated through other independent methods. We thus caution that applying the FVG method should be performed carefully in the era of time-domain astronomy.","PeriodicalId":48646,"journal":{"name":"Universe","volume":"20 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501925","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}
Pub Date : 2024-06-27DOI: 10.3390/universe10070278
Ka-Wah Wong, Helen R. Russell, Jimmy A. Irwin, Nico Cappelluti, Adi Foord
Hot gas around a supermassive black hole (SMBH) should be captured within the gravitational “sphere of influence”, characterized by the Bondi radius. Deep Chandra observations have spatially resolved the Bondi radii of five nearby SMBHs that are believed to be accreting in hot accretion mode. Contrary to earlier hot accretion models that predicted a steep temperature increase within the Bondi radius, none of the resolved temperature profiles exhibit such an increase. The temperature inside the Bondi radius appears to be complex, indicative of a multi-temperature phase of hot gas with a cooler component at about 0.2–0.3 keV. The density profiles within the Bondi regions are shallow, suggesting the presence of strong outflows. These findings might be explained by recent realistic numerical simulations that suggest that large-scale accretion inside the Bondi radius can be chaotic, with cooler gas raining down in some directions and hotter gas outflowing in others. With an angular resolution similar to Chandra and a significantly larger collecting area, AXIS will collect enough photons to map the emerging accretion flow within and around the “sphere of influence” of a large sample of active galactic nuclei (AGNs). AXIS will reveal transitions in the inflow that ultimately fuels the AGN, as well as outflows that provide feedback to the environment. This White Paper is part of a series commissioned for the AXIS Probe Concept Mission; additional AXIS White Papers can be found at the AXIS website.
{"title":"Prospects for AGN Studies with AXIS: AGN Fueling—Resolving Hot Gas inside Bondi Radius of SMBHs","authors":"Ka-Wah Wong, Helen R. Russell, Jimmy A. Irwin, Nico Cappelluti, Adi Foord","doi":"10.3390/universe10070278","DOIUrl":"https://doi.org/10.3390/universe10070278","url":null,"abstract":"Hot gas around a supermassive black hole (SMBH) should be captured within the gravitational “sphere of influence”, characterized by the Bondi radius. Deep Chandra observations have spatially resolved the Bondi radii of five nearby SMBHs that are believed to be accreting in hot accretion mode. Contrary to earlier hot accretion models that predicted a steep temperature increase within the Bondi radius, none of the resolved temperature profiles exhibit such an increase. The temperature inside the Bondi radius appears to be complex, indicative of a multi-temperature phase of hot gas with a cooler component at about 0.2–0.3 keV. The density profiles within the Bondi regions are shallow, suggesting the presence of strong outflows. These findings might be explained by recent realistic numerical simulations that suggest that large-scale accretion inside the Bondi radius can be chaotic, with cooler gas raining down in some directions and hotter gas outflowing in others. With an angular resolution similar to Chandra and a significantly larger collecting area, AXIS will collect enough photons to map the emerging accretion flow within and around the “sphere of influence” of a large sample of active galactic nuclei (AGNs). AXIS will reveal transitions in the inflow that ultimately fuels the AGN, as well as outflows that provide feedback to the environment. This White Paper is part of a series commissioned for the AXIS Probe Concept Mission; additional AXIS White Papers can be found at the AXIS website.","PeriodicalId":48646,"journal":{"name":"Universe","volume":"1 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501928","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}
Pub Date : 2024-06-27DOI: 10.3390/universe10070279
Che-Jui Chang, Jean-Fu Kiang
The Fermi bubbles and the eROSITA bubbles around the Milky Way Galaxy are speculated to be the aftermaths of past jet eruptions from a supermassive black hole in the galactic center. In this work, a 2.5D axisymmetric relativistic magnetohydrodynamic (RMHD) model is applied to simulate a jet eruption from our galactic center and to reconstruct the observed Fermi bubbles and eROSITA bubbles. High-energy non-thermal electrons are excited around forward shock and discontinuity transition regions in the simulated plasma distributions. The γ-ray and X-ray emissions from these electrons manifest patterns on the skymap that match the observed Fermi bubbles and eROSITA bubbles, respectively, in shape, size and radiation intensity. The influence of the background magnetic field, initial mass distribution in the Galaxy, and the jet parameters on the plasma distributions and hence these bubbles is analyzed. Subtle effects on the evolution of plasma distributions attributed to the adoption of a galactic disk model versus a spiral-arm model are also studied.
{"title":"Reconstruction of Fermi and eROSITA Bubbles from Magnetized Jet Eruption with Simulations","authors":"Che-Jui Chang, Jean-Fu Kiang","doi":"10.3390/universe10070279","DOIUrl":"https://doi.org/10.3390/universe10070279","url":null,"abstract":"The Fermi bubbles and the eROSITA bubbles around the Milky Way Galaxy are speculated to be the aftermaths of past jet eruptions from a supermassive black hole in the galactic center. In this work, a 2.5D axisymmetric relativistic magnetohydrodynamic (RMHD) model is applied to simulate a jet eruption from our galactic center and to reconstruct the observed Fermi bubbles and eROSITA bubbles. High-energy non-thermal electrons are excited around forward shock and discontinuity transition regions in the simulated plasma distributions. The γ-ray and X-ray emissions from these electrons manifest patterns on the skymap that match the observed Fermi bubbles and eROSITA bubbles, respectively, in shape, size and radiation intensity. The influence of the background magnetic field, initial mass distribution in the Galaxy, and the jet parameters on the plasma distributions and hence these bubbles is analyzed. Subtle effects on the evolution of plasma distributions attributed to the adoption of a galactic disk model versus a spiral-arm model are also studied.","PeriodicalId":48646,"journal":{"name":"Universe","volume":"37 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501929","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}
Pub Date : 2024-06-26DOI: 10.3390/universe10070277
Junjie Lu, Xin Wu
A renormalized group improved Schwarzschild black hole spacetime contains two quantum correction parameters. One parameter γ represents the identification of cutoff of the distance scale, and another parameter Ω stems from nonperturbative renormalization group theory. The two parameters are constrained by the data from the shadow of M87* central black hole. The dynamics of electrically charged test particles around the black hole are integrable. However, when the black hole is immersed in an external asymptotically uniform magnetic field, the dynamics are not integrable and may allow for the occurrence of chaos. Employing an explicit symplectic integrator, we survey the contributions of the two parameters to the chaotic dynamical behavior. It is found that a small change of the parameter γ constrained by the shadow of M87* black hole has an almost negligible effect on the dynamical transition of particles from order to chaos. However, a small decrease in the parameter Ω leads to an enhancement in the strength of chaos from the global phase space structure. A theoretical interpretation is given to the different contributions. The term with the parameter Ω dominates the term with the parameter γ, even if the two parameters have same values. In particular, the parameter Ω acts as a repulsive force, and its decrease means a weakening of the repulsive force or equivalently enhancing the attractive force from the black hole. On the other hand, there is a positive Lyapunov exponent that is universally given by the surface gravity of the black hole when Ω ≥ 0 is small and the external magnetic field vanishes. In this case, the horizon would influence chaotic behavior in the motion of charged particles around the black hole surrounded by the external magnetic field. This point can explain why a smaller value of the renormalization group parameter would much easily induce chaos than a larger value.
{"title":"Effects of Two Quantum Correction Parameters on Chaotic Dynamics of Particles Near Renormalized Group Improved Schwarzschild Black Holes","authors":"Junjie Lu, Xin Wu","doi":"10.3390/universe10070277","DOIUrl":"https://doi.org/10.3390/universe10070277","url":null,"abstract":"A renormalized group improved Schwarzschild black hole spacetime contains two quantum correction parameters. One parameter γ represents the identification of cutoff of the distance scale, and another parameter Ω stems from nonperturbative renormalization group theory. The two parameters are constrained by the data from the shadow of M87* central black hole. The dynamics of electrically charged test particles around the black hole are integrable. However, when the black hole is immersed in an external asymptotically uniform magnetic field, the dynamics are not integrable and may allow for the occurrence of chaos. Employing an explicit symplectic integrator, we survey the contributions of the two parameters to the chaotic dynamical behavior. It is found that a small change of the parameter γ constrained by the shadow of M87* black hole has an almost negligible effect on the dynamical transition of particles from order to chaos. However, a small decrease in the parameter Ω leads to an enhancement in the strength of chaos from the global phase space structure. A theoretical interpretation is given to the different contributions. The term with the parameter Ω dominates the term with the parameter γ, even if the two parameters have same values. In particular, the parameter Ω acts as a repulsive force, and its decrease means a weakening of the repulsive force or equivalently enhancing the attractive force from the black hole. On the other hand, there is a positive Lyapunov exponent that is universally given by the surface gravity of the black hole when Ω ≥ 0 is small and the external magnetic field vanishes. In this case, the horizon would influence chaotic behavior in the motion of charged particles around the black hole surrounded by the external magnetic field. This point can explain why a smaller value of the renormalization group parameter would much easily induce chaos than a larger value.","PeriodicalId":48646,"journal":{"name":"Universe","volume":"30 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501927","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}
Pub Date : 2024-06-25DOI: 10.3390/universe10070273
Helen R. Russell, Laura A. Lopez, Steven W. Allen, George Chartas, Prakriti Pal Choudhury, Renato A. Dupke, Andrew C. Fabian, Anthony M. Flores, Kristen Garofali, Edmund Hodges-Kluck, Michael J. Koss, Lauranne Lanz, Bret D. Lehmer, Jiang-Tao Li, W. Peter Maksym, Adam B. Mantz, Michael McDonald, Eric D. Miller, Richard F. Mushotzky, Yu Qiu, Christopher S. Reynolds, Francesco Tombesi, Paolo Tozzi, Anna Trindade-Falcão, Stephen A. Walker, Ka-Wah Wong, Mihoko Yukita, Congyao Zhang
Stellar and black hole feedback heat and disperse surrounding cold gas clouds, launching gas flows off circumnuclear and galactic disks, producing a dynamic interstellar medium. On large scales bordering the cosmic web, feedback drives enriched gas out of galaxies and groups, seeding the intergalactic medium with heavy elements. In this way, feedback shapes galaxy evolution by shutting down star formation and ultimately curtailing the growth of structure after the peak at redshift 2–3. To understand the complex interplay between gravity and feedback, we must resolve both the key physics within galaxies and map the impact of these processes over large scales, out into the cosmic web. The Advanced X-ray Imaging Satellite (AXIS) is a proposed X-ray probe mission for the 2030s with arcsecond spatial resolution, large effective area, and low background. AXIS will untangle the interactions of winds, radiation, jets, and supernovae with the surrounding interstellar medium across the wide range of mass scales and large volumes driving galaxy evolution and trace the establishment of feedback back to the main event at cosmic noon. This white paper is part of a series commissioned for the AXIS Probe mission concept; additional AXIS white papers can be found at the AXIS website.
恒星和黑洞的反馈作用加热并分散了周围的冷气体云，使气体流脱离环核和星系盘，产生了动态的星际介质。在与宇宙网接壤的大尺度上，反馈将富集的气体驱赶出星系和星系群，为星系际介质播下重元素的种子。通过这种方式，反馈通过关闭恒星形成来影响星系的演化，并最终在红移 2-3 峰值之后抑制结构的增长。为了理解引力和反馈之间复杂的相互作用，我们必须解决星系内部的关键物理问题，并绘制这些过程对大尺度宇宙网的影响图。高级 X 射线成像卫星（AXIS）是一项拟于 2030 年代执行的 X 射线探测任务，具有弧秒空间分辨率、大有效面积和低背景。AXIS 将在广泛的质量尺度和大体积范围内解开风、辐射、喷流和超新星与周围星际介质的相互作用，并追溯到宇宙正午的主要事件。本白皮书是 AXIS 探测器任务概念委托编写的系列白皮书之一；其他 AXIS 白皮书可在 AXIS 网站上查阅。
{"title":"The Evolution of Galaxies and Clusters at High Spatial Resolution with Advanced X-ray Imaging Satellite (AXIS)","authors":"Helen R. Russell, Laura A. Lopez, Steven W. Allen, George Chartas, Prakriti Pal Choudhury, Renato A. Dupke, Andrew C. Fabian, Anthony M. Flores, Kristen Garofali, Edmund Hodges-Kluck, Michael J. Koss, Lauranne Lanz, Bret D. Lehmer, Jiang-Tao Li, W. Peter Maksym, Adam B. Mantz, Michael McDonald, Eric D. Miller, Richard F. Mushotzky, Yu Qiu, Christopher S. Reynolds, Francesco Tombesi, Paolo Tozzi, Anna Trindade-Falcão, Stephen A. Walker, Ka-Wah Wong, Mihoko Yukita, Congyao Zhang","doi":"10.3390/universe10070273","DOIUrl":"https://doi.org/10.3390/universe10070273","url":null,"abstract":"Stellar and black hole feedback heat and disperse surrounding cold gas clouds, launching gas flows off circumnuclear and galactic disks, producing a dynamic interstellar medium. On large scales bordering the cosmic web, feedback drives enriched gas out of galaxies and groups, seeding the intergalactic medium with heavy elements. In this way, feedback shapes galaxy evolution by shutting down star formation and ultimately curtailing the growth of structure after the peak at redshift 2–3. To understand the complex interplay between gravity and feedback, we must resolve both the key physics within galaxies and map the impact of these processes over large scales, out into the cosmic web. The Advanced X-ray Imaging Satellite (AXIS) is a proposed X-ray probe mission for the 2030s with arcsecond spatial resolution, large effective area, and low background. AXIS will untangle the interactions of winds, radiation, jets, and supernovae with the surrounding interstellar medium across the wide range of mass scales and large volumes driving galaxy evolution and trace the establishment of feedback back to the main event at cosmic noon. This white paper is part of a series commissioned for the AXIS Probe mission concept; additional AXIS white papers can be found at the AXIS website.","PeriodicalId":48646,"journal":{"name":"Universe","volume":"34 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501930","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：