Damghan University PressIranian Journal of Astronomy and Astrophysics2322-492411420250129Dark Energy Evolution: Non-Interacting and Interacting Cases24527346210.22128/ijaa.2025.861.1190ENSaeed Noori GashtiDepartment of Physics, Faculty of Basic Sciences, University of Mazandaran, Babolsar, IranMohammad Reza AlipourDepartment of Physics, Faculty of Basic Sciences, University of Mazandaran, Babolsar, IranMohammad Ali S. AfsharDepartment of Physics, Faculty of Basic Sciences, University of Mazandaran, Babolsar, IranJafar SadeghiDepartment of Physics, Faculty of Basic Sciences, University of Mazandaran, Babolsar, IranJournal Article20240814 <span class="fontstyle0">In this paper, we study dark energy from two different perspectives, challenging a two-field scenario in two forms: non-interacting and interacting. We investigate the evolution of dark energy in a Friedmann-Robertson-Walker space-time that is spatially homogeneous and isotropic and filled with two components: dark energy and a barotropic fluid. We examine this evolution from two different perspectives: noninteracting and interacting; and we did it by selecting a suitable ansatz for the scale factor that reflects the transition of the universe from the early decelerating phase to the late accelerated stage. We calculate parameters and quantities such as pressure </span><span class="fontstyle2">p</span><span class="fontstyle0">, energy density </span><span class="fontstyle2">ρ</span><span class="fontstyle0">, equation of state (EoS), deceleration parameter </span><span class="fontstyle2">q</span><span class="fontstyle0">, etc., and compare the results of these two cases with the latest observational data as well as other works in the literature. We discuss the stability of these two different scenarios by calculating the sound speed. We also show whether different energy conditions are satisfied or violated. Then, we explore the evolutionary paths and the dynamical analysis of the model with the help of important tools such as the statefinder diagnostic </span><span class="fontstyle3">(</span><span class="fontstyle2">r, s</span><span class="fontstyle3">) </span><span class="fontstyle0">and discuss the results in detail. Finally, we reconstruct the scalar field’s potential and test some conjectures using the equation of the state of dark energy and the relation between energy density and pressure with the scalar field and potential. Then, we discuss the results in detail. An important issue that we found in this calculation is the dissatisfaction of the swampland conjectures with this model in non-interacting cases but in the face of swampland conjectures, some acceptable range for </span><span class="fontstyle2">t < </span><span class="fontstyle3">2 </span><span class="fontstyle0">is seen for all universes in interacting cases.</span>https://ijaa.du.ac.ir/article_462_3df782ad8d85ce0ef5a708ea62a7ec10.pdfDamghan University PressIranian Journal of Astronomy and Astrophysics2322-492411420250219On the Generation and Dissipation of Magnetic Energy During a Shear-Flow Driven Instability in Space Plasmas27529046410.22128/ijaa.2025.931.1203ENMahboub HosseinpourFaculty of Physics, University of Tabriz, Tabriz, P.O.Box:16471, Iran0000-0001-8296-6981Journal Article20241226A well-known shear flow-driven instability, namely the Kelvin‐Helmholtz instability (KHI), establishes important changes in the macroscopic dynamics of some space magnetized plasmas such as the solar corona, astrophysical jets and the Earth's magnetopause. We use two-dimensional resistive magnetohydrodynamic (MHD) simulations to investigate the generation and dissipation of magnetic energy during KHI in a compressible plasma with an initial uniform magnetic field parallel to the direction of streaming flow. Regardless of the resistivity value, the results show that, up to a specific time, amplification of magnetic energy, in particular in the linear and early nonlinear phases of KHI happens by the flow's work on the magnetic field. This work is mainly efficient on the boundaries of growing vortices of KHI. As the KHI proceeds into the fully nonlinear (turbulent) phase, magnetic energy dissipation via Ohmic heating becomes significant, and eventually balances the flow's work, so the magnetic energy becomes saturated. We also found that increasing the plasma resistivity weakens the mechanism of generating magnetic energy, and may even be completely suppressed in a highly collisional fluid.https://ijaa.du.ac.ir/article_464_c6fff6e851a655c90bfd6aadfd394317.pdfDamghan University PressIranian Journal of Astronomy and Astrophysics2322-492411420250101Observational Status of Zero-Point Length Cosmic Inflation29130946910.22128/ijaa.2025.918.1200ENElahe PourmohseniDepartment of Theoretical Physics, Faculty of Science, University of Mazandaran, P.O. Box 47416--95447, Babolsar, IranKourosh NozariDepartment of Theoretical Physics, Faculty of Science, University of Mazandaran, P.O. Box 47416--95447, Babolsar, Iran0000-0003-4368-5823Amin Nassiri-RadDepartment of Physics, K. N. Toosi University of Technology, P.O. Box 15875--4416, Tehran, IranJournal Article20241207We examine observational status of cosmological inflation with a zero-point length. By considering the zero-point length correction to the geometric part of the field equations, specially the Hubble parameter, we derive modified background equations, slow-roll parameters and inflation observables including scalar spectral index and tensor-to-scalar ratio in this setup. We conduct numerical analysis on a power-law inflation as a toy model and also some other inflation potentials to assess the impact of a minimum length on the inflationary cosmology. In this regard, we compare our results with recent data from Planck 2018 TT, TE, EE +lowE +lensing, Planck 2018 TT, TE, EE +lowE +lensing+BK15, and Planck 2018 TT, TE, EE +lowE +lensing+ BK15+ BAO at the $\%68$ and $\%95$ levels of confidence. We find that the impact of the zero-point length varies across different potentials and its characteristic value is of different orders of magnitude (in units of the Planck length), determined based on the various types of the potentials. We show that, while some inflation potentials fall outside the mentioned datasets' confidence levels in the absence of the zero-point length, they are in good agreement with the same datasets in the presence of the zero-point length. In this comparison, we obtain a range of consistency for the zero-point length with the mentioned observational data.https://ijaa.du.ac.ir/article_469_b3334e54d88961f8efe2741a3ff455ca.pdfDamghan University PressIranian Journal of Astronomy and Astrophysics2322-492411420250517Magnetic Braking of the Rotational Molecular Cloud Cores, Revisited31132448010.22128/ijaa.2025.932.1204ENAbbas EbrahimiDepartment of Theoretical Physics, Faculty of Science, University of Mazandaran, P. O. Box 47416-95447, Babolsar, IranMohsen Nejad-AsgharDepartment of Theoretical Physics, Faculty of Science, University of Mazandaran, P. O. Box 47416-95447, Babolsar, IranJournal Article20241228The phenomenon of magnetic braking is one of the significant physical effects of the magnetic field in rotating molecular clouds. Here, we revisit the work of Nakano (1989). In addition to receiving his results, we investigate the effects of the density ratio (between periphery of the core to its mean density), and the density condensations around the core. We consider the density profile of the surrounding medium as r<sup>-η</sup>, where r is the distance from the core center and η is a constant between 0 and 4. Regarding the presence of some dense regions around the molecular cloud cores, a Gaussian function is added to the density profile to represent these condensations in the surrounding medium. The numerical method is used in the Laplace space to ascertain the dependency of the angular velocity of the core to the time. The results show that for larger η values, the time scale of the magnetic braking increases. Moreover, the presence of condensation does not have a significant effect on the magnetic braking. Also, the the results show that the magnetic braking being stronger with increasing density ratio. This increasing indicates that the magnetic field is more firmly bonded to the bulk materials. This effect strengthens the magnetic tension force and slows down the core faster that indicates the importance of the magnetic braking. The results show that increasing density slope and/or decreasing density ratio are somewhat effective in weakening the magnetic braking and resolving its catastrophic effect. https://ijaa.du.ac.ir/article_480_09d1e77b627b7ff47efdd77af279c49e.pdfDamghan University PressIranian Journal of Astronomy and Astrophysics2322-492411420250517Investigation of the Effect of Density Gradients in Fuel Pellets on Filamentation Electromagnetic Instability during Beam-Plasma Interactions in Inertial Confinement Fusion32533347910.22128/ijaa.2025.975.1208ENMohammad MahdaviDepartment of Physics, Faculty of Basic Sciences, University of Mazandaran, P.O. Box 47415-416, Babolsar, IranZeinab BizhaniDepartment of Physics, Faculty of Basic Sciences, University of Mazandaran, P.O. Box 47415-416, Babolsar, IranHengameh KhanzadehDepartment of Physics, Faculty of Basic Sciences, University of Mazandaran, P.O. Box 47415-416, Babolsar, IranJournal Article20250306The transfer of a beam of high-energy particles, such as electrons, to the center of a fuel pellet is a significant aspect of plasma fusion processes. When the beam is directed toward the center of the fuel pellet, a counter-current is generated by the plasma electrons surrounding the pellet. This current leads to the production of an electromagnetic field. The growth of this electromagnetic field results in the appearance of instabilities, including filamentation instability within the plasma medium. Furthermore, the gradual growth of these instabilities disrupts energy transfer to the fuel pellet, hindering the achievement of ideal ignition conditions. The present study investigated the effects of parameters such as the density gradient of the fuel pellet, thermal anisotropy and the relativistic mass factor on filamentation instability in a beam-plasma system that includes non-relativistic background electrons and a relativistic mono-energetic electron beam. By linearizing Maxwell-Vlasov equations, the dispersion relation for filamentation instability was derived. While solving the dispersion equation and calculating the instability growth rate, it was observed that with increasing the scale length of the density gradient, due to the higher collision rate and the increase in energy transfer to the plasma particles, the growth rate of filamentation instability decreased. Additionally, it was found that increasing the relativistic mass factor and thermal anisotropy fraction leads to an increase in the instability growth rate due to increased internal energy dissipation.https://ijaa.du.ac.ir/article_479_52787311d438958faf04d671ae36d1a6.pdfDamghan University PressIranian Journal of Astronomy and Astrophysics2322-492411420250629SoHO/EIT, Stereo-A, and SDO/AIA View for Solar Coronal Differential Rotation33535149010.22128/ijaa.2025.996.1210ENZahra ShokriDepartment of Physics, Faculty of Science, University of Zanjan, University Blvd., Postal Code 45371-38791, Zanjan, Iran0000-0003-4177-0645Nasibe AlipourDepartment of Physics, University of Guilan, Rasht, 41335-1914, Iran0000-0003-3643-5121Hasan RezaeiDepartment of Geography, Faculty of Basic Sciences, Imam Ali Nazaja University, Postal Code: 1317893471, Tehran, IranMahdi SimiariDepartment of physics, Faculty of Science, Imam Ali University, Postal Code: 1317893471, Tehran, IranHossien SafariDepartment of Physics, Faculty of Science, University of Zanjan, University Blvd., Postal Code 45371-38791, Zanjan, Iran0000-0003-2326-3201Journal Article20250424Differential rotation of the solar corona is challenging due to the nature of short-wavelength emissions. In this study, we aim to measure coronal differential rotation from different perspectives using observations from SoHO/EIT at 195 Å, Stereo-A/EUVI at 195 Å, and SDO/AIA at 193 Å on June 1st, 2010. To achieve this, we apply a method based on Zernike Moments and Support Vector Machine (SVM) to identify and track coronal bright points (CBPs) over a 10 hour observation period. In the heliographic coordinate system, we determine the angular velocity of the corona by fitting a linear time-dependent function to the central meridian distance of each CBP. By analyzing a collection of CBPs in the solar equatorial central region (within ±50º in longitude and latitude) from each perspective, we obtain the equatorial rotation rate (A) and the latitudinal rotation gradient (B). The results indicate values of 14.32, 14.54, and 14.51 ºday-1 with -2.93, -4.03, and -3.16 ºday-1 for SoHO, Stereo-A, and SDO, respectively.https://ijaa.du.ac.ir/article_490_556f2f213d04d417f5e89ee0d0a5ded2.pdf