Research Article Field Localization and Density Cavitation in Low-Beta Plasmas Motilal Rinawa , 1 Prashant Chauhan , 2 Sintu Kumar , 3 ManojKumarSingh , 4 HariKumarSingh , 5 Amit Sharma , 6 andR.P.Sharma 1 1 Centre for Energy Studies, Indian Institute of Technology Delhi, Delhi 110016, India 2 Department of Physics and Material Science and Engineering, Jaypee Institute of Information Technology, Noidar, Uttar Pradesh, India 3 Department of Physics, DeenDayal Upadhyay Gorakhpur University, Gorakhpur-273009, Uttar Pradesh, India 4 Department of Mechanical Engineering, Faculty of Engineering and Technology, MJP Rohilkhand University, Bareilly, Uttar Pradesh, India 5 Electronics and Communication Engineering, M. J. P. Rohilkhand University, Bareilly, Uttar Pradesh, India 6 Department of Physics, D.A.V. (PG) College, Dehradun, India Correspondence should be addressed to Prashant Chauhan; prashant.chauhan@jiit.ac.in Received 28 May 2021; Revised 1 November 2021; Accepted 9 November 2021; Published 28 November 2021 Academic Editor: Yongtao Zhao Copyright©2021MotilalRinawaetal.isisanopenaccessarticledistributedundertheCreativeCommonsAttributionLicense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. In the present paper, filamentous structure formation, associated turbulent spectrum, and density cavity formation phenomena havebeeninvestigatedforlow-β plasma (β ≪ m e /m i ) applicabletotheauroralregion.Asetofdimensionlessequationsgoverning thedynamicsofthreedimensionallypropagatinginertialAlfv´ enwave(3D-IAW)andperpendicularlypropagatingmagnetosonic wave (PMSW) has been developed. Ponderomotive force due to 3D-IAW has been included in the dynamics of the PMSW. Numerical simulation has been performed to study the nonlinear coupling of these two waves. From the obtained results, we foundthatthefieldintensitylocalizationtakesplacewhichmayfurtherleadtotheadditionaldissipation/turbulenceprocessfor particle heating and acceleration in space plasma. e associated turbulent spectrum is obtained with scaling nearly k − 4.28 at smaller scales (in the dissipation range). Relevance of the obtained results with the observations reported by various spacecrafts such as Hawkeye and Heos 2 has been discussed. Also, density fluctuations (depletion) of ∼0.10 n 0 are calculated, which are consistent with the FAST spacecraft observation reported. 1.Introduction Alfv´ en waves (AWs) were first theoretically predicted by Hannes Alfv´ en in 1942 and later verified experimentally by Bostick and Levine in [1]. ese are the low-frequency elec- tromagnetic waves propagating along the background mag- netic field in space and laboratory plasmas [2, 3]. ese waves arenondispersiveinnaturebutcanobtaindispersiveproperties due to finite frequency correction and finite electron inertia effects [4] in low-β plasmas with β ≪ m e /m i (wherem e /m i is theratiooftheelectronmasstotheionmassand β istheratio of the thermal pressure to the magnetic pressure). When their perpendicular length scales become finite and comparable to the electron inertial length [5] or to the ion gyroradius/finite gyroradius, these waves become dispersive in nature and are known as dispersive Alfv´ en waves (DAWs). e most vital physical property of the DAWs is the presence of the finite parallel electric field [6]. Inertial Alfv´ en waves (IAWs) are known to play a vital role in the energization of the auroral plasma [7, 8]. In the literature, several authors have studied the strong density depletion in the low-β plasma. Wu et al. [9] dis- cussed the density depletion in the corona due to the presence of beams of energetic particles and magnetic compression. Many researchers [10, 11] have pointed out the role of solitary IAWs, which are accompanied by both density dips andhumpsinauroralparticleheating.Intheliterature,ithas been suggested that these cavities are associated with the ponderomotivenonlinearityoftheinertialAlfv´ enwave[12]. Hindawi Laser and Particle Beams Volume 2021, Article ID 2891080, 9 pages https://doi.org/10.1155/2021/2891080