Thanks.
What is 'negentropy' has been a headache of mine.
Now I Think negentropy must be referred to quantum states and their information content as 'possibilities'. As instance in the ER=EPR analogy it is used, but not the Word negentropy, because it is a controversy yet.
There pure states are defined by no difference in entropy, but it also contains the 'codes' for 'reality' and it gives a 'compactification' through the error correction, or state function reduction, as
"the Ryu-Takayanagi formula and the negativity of tripartite information... p 19.
For a general (mixed) tripartite quantum state, I_3 can take any real value. It is zero, though, for any tripartite pure state of ABC, since in that case SABC = 0 and e.g. regions A and BC, being complementary, have the same entropy and therefore make cancelling contributions to I_3."
This means we have a pure quantum state. No thermodynamics? Or no difference between entropy - negentropy? We have a state with all possibilities, no state function reduction.
Or said another way, no error correction yet. What cause the error correction here? It is the 3-surface of mixed states...
Preskill et co.: "Thus, for a holographic state and for any partition of the boundary into four regions A;B;C;D; nonzero contributions to I_3(A;B;C) can arise only from the distilled multipartite states trapped in residual regions."
Distilled = condensed, I think. What enters the eq.? Time? (that is also speed?)They think QG?
Negativity is from the RT-formula, they say.
"For holographic states and codes, the non-positivity of I_3 is not ensured in general, because of the potential (small) violations of the RT formula. In some special cases, though, RT holds exactly, and the non-positivity of I_3 then follows."
the potential (small) violations of the RT formula - is the state function reduction, I Think.
https://arxiv.org/pdf/1503.06237.pdf
http://tgdtheory.fi/public_html/articles/tensornet.pdf
P. Hayden, M. Headrick, and A. Maloney, Holographic mutual information is
monogamous, Phys. Rev. D 87 (2013) 046003.
L. Susskind and E. Witten, The Holographic bound in anti-de Sitter space,
hep-th/9805114.