Is the open Catalan a gambit? I have been looking at the open variation of the Catalan game, where White seems not to extremely worry about conceding the pawn with 4...dxc4, going for calm development instead. One notorious example is the below game where Black eventually gives back the material playing 9...b5 without (apparent) preparation; however, I do not see why this is necessary and the questions is whether the underlying idea for White behind this opening is to just gambit without really looking at any way of taking back the c4 pawn unless re-offered.

    [fen ""]
    [Event "WCC Match 2006"]
[Site "Elista RUS"]
[Date "2006.09.23"]
[EventDate "?"]
[Round "1"]
[Result "1-0"]
[White "Vladimir Kramnik"]
[Black "Veselin Topalov"]
[ECO "E04"]
[WhiteElo "2743"]
[BlackElo "2813"]
[PlyCount "149"]

    1.d4 Nf6 2.c4 e6 3.Nf3 d5 4.g3 dxc4 5.Bg2 Bb4+ 6.Bd2 a5 7.Qc2 Bxd2+ 8.Qxd2 c6 9.a4 b5 10.axb5 cxb5 11.Qg5 O-O 12.Qxb5 Ba6 


Another example is this other below game where again Black gives back the pawn after quite a few moves although it seems it could have defended and kept it, had it wanted to, preparing ...b5 after proper set up and development. I have purposely chosen to display games by Kramnik as he is a major player of the Catalan games and I assume his continuations in these positions are theoretically correct (hence it all boils down to what Black chooses).

[fen ""]
[Event "Corus"]
[Site "Wijk aan Zee NED"]
[Date "2007.01.21"]
[Round "8"]
[White "Vladimir Kramnik"]
[Black "Magnus Carlsen"]
[Result "1/2-1/2"]
[ECO "E04"]
[WhiteElo "2766"]
[BlackElo "2690"]
[TimeControl ""]
[Time ""]
[PlyCount "55"]
[EventDate "2007.01.13"]
[Annotator ""]

1. Nf3 Nf6 2. c4 e6 3. g3 d5 4. d4 dxc4 5. Bg2 a6 6. O-O Nc6 7. e3 Bd7 8. Nc3 Nd5 9. Nd2 Nb6 10. Qe2 Na5 11. Nde4 Be7 12. Nc5 Bc6 13. Bxc6+ Nxc6 14. Nxb7 Qc8 15. Nc5 O-O 16. N5a4 Nb4 17. Bd2 Rd8 18. a3 Nc6 19. Rac1 Rb8 20. Rfd1 e5 21.Nxb6 cxb6 22. Qxc4 exd4 23. Ne4 dxe3 24. Bxe3 Rxd1+ 25. Rxd1 Qb7 26. Rc1 Ne5 27. Qc7 f6 


Does White play a gambit in the open Catalan or is the c4 pawn doomed to be taken back necessarily, at some point in the game?
Generally it seems to me if you want to keep the pawn on c4 with b5, white can play a4 which is cumbersome for black as protecting the pawn on b5 with c6 or a6 runs into pins on the a file or the h1-a8 diagonal. Even if you did manage this setup with pawns on a6, b5, c6 and c4 and maybe the bishop on b7 (or moving the rook out of the pins), black's light-squared bishop is very passive and moving any of these four pawns will create weaknesses or lose a pawn.

So yes, you could call it a gambit I guess.