A nice detour. The knights are very good with such  maneuvers. They see an outpost and run towards it without worrying about  the speed.
1. d2d4  1... g8f6  2. g1f3  2... d7d5  3. c1f4  3... e7e6  4. e2e3  4... f8d6  5. b1d2  5... b7b6  6. f4g3  6... e8g8  7. f1d3  7... c8a6  The swap of the light-squared bishops is one of the safest ideas against  the London. 8. a1c1  8... a6d3 It is interesting that in this line it is White who  usually doubles the opponent's pawns after capturing on d6. 9. c2d3  9... c7c5  10. d1a4 Aronian is trying to inhibit the opponent's normal  development. 10... d6e7 Carlsen moves the bishop away from the vulnerable  position, thus preparing both Nb8-d7 and the move in the game. 11. e1g1  11... d8d7  12. a4d7 After this trade White has no advantage at all. 12... b8d7  13. c1c2  13... a7a5 In fact, Black's position is much easier to  play. He has a clear play on the queenside, and the annoying white's  bishop influence can be easily bypassed by the maneuver Ra8-a7-b7.  Speaking of the white bishop, it might soon become a problematic, empty  bishop: seemingly active, but in reality, ineffective. 14. a2a4 Probably  missing Black's next move.