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EMERGENCE, COMPLEXITE, UNIVERSALITE des SYSTEMES a N CORPS:NOYAUX, ATOMES FROIDS, AGREGATS METALLIQUES, MOLECULES, ...
P. Schuck
IPNO
CONTENT
Nuclear Mean Field: dead end.
Inclusion of quantal fluctuations and more correlations
Second RPA; Coupled Cluster; TDDM.
Overlap with Chemistry
Overlap with Cold Atoms
Overlap with small metallic clusters
Conclusions
MEAN FIELD APPROACHAbout 250 Skyrme forces and nuclear EDF’s !!Stone et al
In any case quantal fluctuations have to be included: Tselyaev:
New parameter fit!! Very large program!!
10 15 20 25 30E (MeV)
0
2
4
6
8
B(E
0)
(e2fm
4M
eV
-1)
SRPASSRPA
D
SSRPAF
Second RPA with substraction; monopole spectrum, M. Grasso et al.
GW approach to surface of a solid.
Applications of RPA to molecules.
Pairing in neutron matterVery long nn s-wave scattering length: anns ∼ -18 fm; at low density almost coldatom conditions!
0 0.1 0.2 0.3 0.4 0.5 0.6
kF [fm
-1]
0
0.5
1
1.5
2
2.5
∆ (
MeV
)
BCSChen 93Wambach 93Schulze 96Schwenk 03Fabrocini 05Cao 06dQMC 09
AFDMC 08QMC AV4
0 2 4 6 8 10 12- k
F a
Coupled Cluster Theory (CCT) Applications in Chemistry and nuclei
0.75
0.8
0.85
0.9
0.95
1
1.05
1.1
0 0.1 0.2 0.3 0.4 0.5 0.6
Ec
/ E
cexac
t
G / ∆ε
Gc
BCS p-CCDBCS p-BCCDPBCS
False first order phase transition!
α – Particles Only Exist in Low DensityBEC Phase
Quartetting
0 1 2 3 410-4
10-3
10-2
10-1
k (fm-1)
f pt(
k)
VMC
GFMC
Experiment
0 0.2 0.40
1
2
3
4
5
6
k2 (fm-2)
6 Z
ftr
(k)
/ k2
(
fm2)
LEFT: THSR result; no adjustable parameter; ρ = ρ0/3
RIGHT: GFMC result (R. Wiringa, Pieper, .., RMP); no afjustable parameter
Self-Consistent RPA ↔ Time Dependent Density MatrixTohyama, P. Sch.
i ρ = [hHF, ρ] + vC2
i C2 = ...ρ,C2+ v [C3 ∼ C2 ⊗ C2]
Standard RPA: ground state: Slater;( C2 = 0)
S0χ0 = Ω0Nχ0
Inclusion of C2: → Second RPA: ground state: CCD(S BB+ D
)(χ1
X2
)= Ω
(N TT + N2
)(χ1
X2
)(1)
Self-Consistent RPA:
S [χ1]χ1 = ΩNχ1
SCRPA: all properties like RPA! Goldstone, Ward identities, etcKadanoff-Baym → dead end! Too complicated!!
THANK YOU !