Stochastic models of diffusion with excluded-volume effects are used to model many biological and physical systems at a discrete level. The average properties of the population may be described by a continuum model based on partial differential equations. In this paper we consider multiple interacting subpopulations/species and study how the inter-species competition emerges at the population level. Each individual is described as a finite-size hard core interacting particle undergoing Brownian motion. The link between the discrete stochastic equations of motion and the continuum model is considered systematically using the method of matched asymptotic expansions. The system for two species leads to a nonlinear cross-diffusion system for each subpopulation, which captures the enhancement of the effective diffusion rate due to excluded-volume interactions between particles of the same species, and the diminishment due to particles of the other species. This model can explain two alternative notions of the diffusion coefficient that are often confounded, namely collective diffusion and self-diffusion. Simulations of the discrete system show good agreement with the analytic results.

1.
D.
Helbing
,
Rev. Mod. Phys.
73
,
1067
(
2001
).
2.
P.
Murray
,
C.
Edwards
,
M.
Tindall
, and
P. K.
Maini
,
Phys. Rev. E
80
,
031912
(
2009
).
3.
H.
Van Dyke Parunak
,
R.
Savit
, and
R.
Riolo
, in
Multi-Agent Systems and Agent-Based Simulation
, edited by
J.
Sichman
,
R.
Conte
, and
N.
Gilbert
(
Springer Verlag
,
1998
), pp.
277
283
.
4.
S.
Jabbari-Farouji
and
E.
Trizac
,
J. Chem. Phys.
137
,
054107
(
2012
).
5.
D.
Boda
,
J.
Giri
,
D.
Henderson
,
B.
Eisenberg
, and
D.
Gillespie
,
J. Chem. Phys.
134
,
055102
(
2011
).
6.
B.
Hille
,
Ion Channels of Excitable Membranes
(
Sinauer
,
Sunderland, MA
,
2001
).
7.
M.
Krüger
and
M.
Rauscher
,
J. Chem. Phys.
131
,
094902
(
2009
).
8.
J.
Sun
and
H.
Weinstein
,
J. Chem. Phys.
127
,
155105
(
2007
).
9.
N.
Chen
and
M.
Alber
,
Phys. Rev. E
78
,
061904
(
2008
).
10.
A.
John
,
A.
Schadschneider
,
D.
Chowdhury
, and
K.
Nishinari
,
J. Theor. Biol.
231
,
279
(
2004
).
11.
M.
Bruna
and
S. J.
Chapman
,
Phys. Rev. E
85
,
011103
(
2012
).
12.
M.
Burger
,
M.
Di Francesco
,
J.-F.
Pietschmann
, and
B.
Schlake
,
SIAM J. Math. Anal.
42
,
2842
(
2010
).
13.
L.
Sander
and
T.
Deisboeck
,
Phys. Rev. E
66
,
051901
(
2002
).
14.
D.
Gillespie
,
W.
Nonner
, and
R. S.
Eisenberg
,
J. Phys.: Condens. Matter
14
,
12129
(
2002
).
15.
D. V.
Nicolau
 Jr.
,
J. F.
Hancock
, and
K.
Burrage
,
Biophys. J.
92
,
1975
(
2007
).
17.
R. E.
Baker
and
M. J.
Simpson
,
Physica A
391
,
3729
(
2012
).
18.
M. J.
Simpson
and
K. A.
Landman
,
Physica A
388
,
399
(
2009
).
19.
B.
DiDonna
,
C.
Santangelo
, and
A.
Gopinathan
,
Phys. Rev. E
78
,
031118
(
2008
).
20.
K. A.
Landman
and
A. E.
Fernando
,
Physica A
390
,
3742
(
2011
).
21.
C.
Penington
and
K. A.
Landman
,
Phys. Rev. E
84
,
041120
(
2011
).
22.
S.
Hanna
,
W.
Hess
, and
R.
Klein
,
Physica A
111
,
181
(
1982
).
23.
T. E.
Saunders
,
K. Z.
Pan
,
A.
Angel
,
Y.
Guan
,
J. V.
Shah
,
M.
Howard
, and
F.
Chang
,
Biophys. J.
22
,
558
(
2012
).
24.
B. U.
Felderhof
,
J. Phys. A
11
,
929
(
1978
).
25.
C.
Beenakker
and
P.
Mazur
,
Physica A
120
,
388
(
1983
).
26.
M. H.
Holmes
,
Introduction to Perturbation Methods
(
Springer
,
New York
,
1995
).
27.
L.
Zhornitskaya
and
A. L.
Bertozzi
,
SIAM J. Numer. Anal.
37
,
523
(
2000
).
28.
R.
Erban
,
S. J.
Chapman
, and
P. K.
Maini
, preprint arXiv:0704.1908 (
2007
).
29.
D.
Buzatu
,
F. D.
Buzatu
,
L.
Paduano
, and
R.
Sartorio
,
J. Solution Chem.
36
,
1373
(
2007
).
30.
J. M.
Zielinski
and
S.
Alsoy
,
J. Polym. Sci., Part B: Polym. Phys.
39
,
1496
(
2001
).
31.
S.
Hittmeir
and
A.
Jüngel
,
SIAM J. Math. Anal.
43
,
997
(
2011
).
32.
R. M.
Mazo
,
Brownian Motion: Fluctuations, Dynamics, and Applications
(
Clarendon
,
Oxford
,
2002
).
33.
B. J.
Ackerson
and
L.
Fleishman
,
J. Chem. Phys.
76
,
2675
(
1982
).
34.
A.
Scala
,
T.
Voigtmann
, and
C.
De Michele
,
J. Chem. Phys.
126
,
134109
(
2007
).
35.
G.
Carrero
,
D.
McDonald
,
E.
Crawford
,
G.
de Vries
, and
M. J.
Hendzel
,
Methods
29
,
14
(
2003
).
36.
J.
Braga
,
J. G.
McNally
, and
M.
Carmo-Fonseca
,
Biophys. J.
92
,
2694
(
2007
).
37.
D.
Axelrod
,
D. E.
Koppel
,
J.
Schlessinger
,
E.
Elson
, and
W. W.
Webb
,
Biophys. J.
16
,
1055
(
1976
).
38.
J. A.
Dix
and
A. S.
Verkman
,
Annu. Rev. Biophys.
37
,
247
(
2008
).
39.
V.
González-Pérez
,
B.
Schmierer
,
C. S.
Hill
, and
R. P.
Sear
,
Integr. Biol.
3
,
197
(
2011
).
40.
J. A.
Carrillo
,
A.
Jüngel
,
P. A.
Markowich
,
G.
Toscani
, and
A.
Unterreiter
,
Monatsh. Math.
133
,
1
(
2001
).
41.
C.
Villani
,
Handbook of Mathematical Fluid Dynamics
(
North-Holland
,
Amsterdam
,
2002
), pp.
71
305
.
42.
S.
Chib
and
E.
Greenberg
,
Am. Stat.
49
,
327
(
1995
).
43.
44.
S. R.
De Groot
and
P.
Mazur
,
Non-Equilibrium Thermodynamics
(
North-Holland
,
Amsterdam
,
1962
), Vol.
386
.
45.
P. K.
Gupta
and
A. R.
Cooper
 Jr.
,
Physica
54
,
39
(
1971
).
46.
P.
Degond
,
S.
Génieys
, and
A.
Jüngel
,
C. R. Acad. Sci., Ser. I: Math.
325
,
963
(
1997
).
47.
S.
Kawashima
and
Y.
Shizuta
,
Tôhoku Math. J.
40
,
449
(
1988
).
48.
F. J.
Valdés-Parada
and
J.
Alvarez-Ramírez
,
J. Chem. Phys.
134
,
204709
(
2011
).
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