Magnetic stress, tension and Alfvén response
Research context
research method · conditional · As of 2026-10-10
Magnetic pressure and tension contribute a stress tensor whose divergence gives the Lorentz force in the stated quasistatic limit.
Key knowledge
Magnetic pressure and tension contribute a stress tensor whose divergence gives the Lorentz force in the stated quasistatic limit. A uniform ideal fluid supports transverse Alfvén waves; compressive modes need pressure and propagation-angle dependence.
Values and equations
S_B=(BB-(B^2/2)I)/μ0; v_A=|B|/sqrt(μ0ρ)
- S_B
- Magnetic force stress Pa
- B
- Magnetic field T
- I
- Identity tensor 1
- μ0
- Magnetic permeability H m^-1
- ρ
- Mass density kg m^-3
- v_A
- Alfvén speed m s^-1
Conditions and scope
- The tensor sign below defines a force stress, opposite to the magnetic contribution in the conservative momentum-flux tensor.
- Nonuniform, resistive, collisionless or relativistic media need the appropriate extension.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Astrophysical fluid dynamics: Sections 3–5 and 9: ideal MHD, stress, waves, energy and angular-momentum fluxes (selected source body inspected).
2026-10-10 · Bounded source check of the recorded statement and conditions. This does not certify a unique physical model, reproduce the cited study or replace independent branch review.
Entry details
Permanent link to this entry ↗- Record identity
- research-earth-magnetic-stress
- Revision
- research.1
- Structured reference record
- Postgraduate & research reference