Here's a TL:DR for you: "The analysis presented in this paper indicates that MH370 changed course shortly after it passed the Northern tip of Sumatra and travel

Here's a TL:DR for you: "The analysis presented in this paper indicates that MH370 changed course shortly after it passed the Northern tip of Sumatra and travelled in a southerly direction until it ran out of fuel in the southern Indian Ocean west of Australia. A potential flight path has been reconstructed that is consistent with the satellite data, indicating a last contact location of 34·7°S and 93·0°E, but it is stressed that the sensitivity of the reconstructed flight path to frequency errors is such that there remains significant uncertainty in the final location."