35J10 Schrödinger operator [See also <a href="#code:35Pxx">35Pxx</a>]

35J20 Variational methods for second-order elliptic equations

35J25 Boundary value problems for second-order elliptic equations

35J30 Higher-order elliptic equations [See also <a href="#code:31A30">31A30</a>, <a href="#code:31B30">31B30</a>]

35J35 Variational methods for higher-order elliptic equations

35J40 Boundary value problems for higher-order elliptic equations

35J50 Variational methods for elliptic systems

35J56 Boundary value problems for first-order elliptic systems

35J57 Boundary value problems for second-order elliptic systems

35J58 Boundary value problems for higher-order elliptic systems

35J65 Nonlinear boundary value problems for linear elliptic equations

35J66 Nonlinear boundary value problems for nonlinear elliptic equations

35J67 Boundary values of solutions to elliptic equations

35J86 Linear elliptic unilateral problems and linear elliptic variational inequalities [See also <a href="#code:35R35">35R35</a>, <a href="#code:49J40">49J40</a>]

35J87 Nonlinear elliptic unilateral problems and nonlinear elliptic variational inequalities [See also <a href="#code:35R35">35R35</a>, <a href="#code:49J40">49J40</a>]

35J88  Systems of elliptic variational inequalities  [See also <a href="#code:35R35">35R35</a>, <a href="#code:49J40">49J40</a>]

35J91 Semilinear elliptic equations with Laplacian, bi-Laplacian or poly-Laplacian

35J92 Quasilinear elliptic equations with $p$-Laplacian

35J93 Quasilinear elliptic equations with mean curvature operator

35J99 None of the above, but in this section

35Kxx Parabolic equations and systems [See also <a href="#code:35Bxx">35Bxx</a>, <a href="#code:35Dxx">35Dxx</a>, <a href="#code:35R30">35R30</a>, <a href="#code:35R35">35R35</a>, <a href="#code:58J35">58J35</a>]

35K15 Initial value problems for second-order parabolic equations

35K20 Initial-boundary value problems for second-order parabolic equations

35K30 Initial value problems for higher-order parabolic equations

35K35 Initial-boundary value problems for higher-order parabolic equations