Holder continuous Euler flows with compact support in time

Building on the recent work of C. De Lellis and L. Székelyhidi, we construct global weak solutions to the three-dimensional incompressible Euler equations which are zero outside of a finite time interval and have velocity in the Hölder class C1/5-et,x . By slightly modifying the proof, we show that every smooth solution to incompressible Euler on (−2, 2) × T3 coincides on (−1, 1) × T3 with some Hölder continuous solution that is constant outside (−3/2, 3/2) × T3 . We also propose a conjecture related to our main result that would imply Onsager's conjecture that there exist energy dissipating solutions to Euler whose velocity fields have Hölder exponent 1/3 – ε.