Information Technology Reference
In-Depth Information
1.8
1.6
1.4
1.2
1
0.8
0
0.2
0.4
0.6
0.8
1
1.2
1.4
T
1.8
1.6
1.4
1.2
1
0.8
0
0.2
0.4
0.6
0.8
1
1.2
1.4
T
Specic heat c
V
vs. temperature T for the homopolymer S
2
h
Fig. 6.8.
(left) and for the good
folder S
22
g
(right). The curves are a guide to the eye.
As to standard thermodynamic observables, all the sequences showed very simi-
lar behaviors: to give an example, in Fig. 6.8 we compare the specic heat c
V
of the
homopolymer S
22
h
and of the good folder S
2
g
: both exhibit a peak at the transition,
and on the sole basis of this picture it would be hard to discriminate between a
simple hydrophobic collapse and a folding. The same happens in the case of the
longer homopolymer S
46
h
and the good folder S
4
g
(data not shown). On the other
hand, a dramatic dierence between the homopolymers and the good folders shows
up if we consider the geometric properties of the landscape. In particular, a lot of
information appears to be encoded in the uctuations of the Ricci curvature K
R
,
i.e., of the Laplacian of the potential energy|see Eq. (6.16). We dened a relative
adimensional curvature uctuation as
q
1
N
(hK
R
i
t
hK
R
i
t
)
1
=
(6.25)
N
hK
R
i
t