The various levels of the scientific contacts lie on
the following altitudes
-2,
0,
1,
4,
33,
45,
45,
300,
374,
383,
383,
383,
431,
1000,
1200,
1302,
1600,
1819,
1863,
1863,
1863,
1923,
2065,
2406,
2712,
2840,
2900,
2930,
3000,
3020,
3025,
3099,
3212,
3254,
3400,
3415,
3842,
4000,
4027,
4153,
4807;
... with the following persons
A. Aubry,
S. Blanes,
J. Butcher,
J. Butcher,
N. Chiriano,
N. Chiriano,
S. Cirilli,
G. Dahlquist,
K. Dekker,
T. Eirola,
W. Enright,
L. Euler,
Feng Kang,
M. Funk,
S. Filippov,
A. Frölicher,
E. Hairer,
E. Hairer,
E. Hairer,
E. Hairer,
E. Hairer,
E. Hairer,
P. de la Harpe,
D. Higham,
I. Higueras,
K. in't Hout,
P. van der Houwen,
M. Huhtanen,
W. Hundsdorfer,
J.P. Imhof,
E. Järvenpää,
M. Järvenpää,
L. Jay,
P. Kaps,
A. Kriegl,
W. Kutta,
V.I. Lebedev,
Li Wang Yao,
Ch. Lubich,
Ch. Lubich,
Ch. Lubich,
F. Mazzia,
F. Mazzia,
A.A. Medovikov,
A. Murua,
O. Nevanlinna,
S. Norsett,
A. Ostermann,
B. Owren,
Y. Pétermann,
J. v. Pfaler,
G. de Rham,
M. Roche,
C. Runge,
Shang Zaijiu,
B. Sommeijer,
M. Spijker,
Sun Geng,
J. Verwer,
K. Weierstrass.