Problems / differential-equations
differential-equations / Partial differential equations
Unbounded variation solutions for uniformly elliptic equations in nondivergence form in dimension three
The authors construct smooth Am and smooth solutions um in B2⊂R3 with one fixed ellipticity bound
I≤Am≤281I,
common boundary data and ∥um∥L∞(B2)≤1, but
∥Dum∥L1(B1)→∞.
Thus no interior W1,1 estimate can depend only on dimension and ellipticity. Consequently, no such W1,p estimate exists for any p≥1.
They further obtain a uniformly convergent limit u with measurable uniformly elliptic coefficient matrix A, where
u∈/BVloc(B1).
The construction even rules out coefficient-independent weak-L1 gradient estimates.