Hi,

Thanks for the quick reply :).

Just to make sure I understood correctly. In the shift_kink move,
the Masha head move in time is not restricted to the time segment in which the occupation number in the site remains the same?
As far as I can see from the code implementation, the shift_kink moves Masha head in the time segment were the occupation number remain the same.

Thanks Again :), for clarifying me all those subtle issues...

Snir

On Sat, Jan 2, 2010 at 12:11 PM, Matthias Troyer <troyer@phys.ethz.ch> wrote:

No, it does not restrict ergodicity since shift_kink can move Masha to an adjacent segment

Matthias

On 2 Jan 2010, at 11:05, Snir Gazit wrote:

Hi,

I have yet another question :).

The Insert jump move inserts a kink only in the time segment in which the occupation number of the original and target site don't change. This leads to the restriction on the remove jump (do to detailed balance) that a kink is removed only if in the time segment between the kink and the Masha head the occupation number remains the same.
Am I right?
If so, doesn't this restriction compromise ergodicy because it restricts the paths in which the worm can choose?
Do you think that the computational over head in inserting a kink in an arbitrary position between the last kink (before Masha) and Masha is reasonable?

Thanks allot :)

Snir 

On Wed, Dec 30, 2009 at 1:23 PM, Snir Gazit <snirgaz@tx.technion.ac.il> wrote:

Thanks again :)

On Wed, Dec 30, 2009 at 1:00 PM, Matthias Troyer <troyer@phys.ethz.ch> wrote:

On 30 Dec 2009, at 11:50, Snir Gazit wrote:

> Hi,
>
> One more question regarding the implementation.
>
> Isn't it better to check if the reconnection move is feasible? (same like the close/open move in which IRA and MASHA should be on the same site).
> I understand that the ALPS implementation keeps the jump and reconnection process symmetric. But essentially they are not because a regular jump (where the kink is inserted before MASHA) is always possible unlike the reconnection process.
> Is there is something I missing?

A regular jump is also not symmetric if there is a cutoff in the total occupation number, as is the case for example for spin models.

And actually we make the check for the matrix element as the first thing in the move - we thus do what you propose

Matthias