5. Brouwer Nash, , , . , . , Poincare Picard Brower , 1910,
Jacques Hadamard Luitzen Egbertus Jan Brouwer . Brouwer: , , . ,
Brouwer. 5 P. Bohl n = 3. , , Nash, John Nash , , , 4 , : The Nash
Equilibrium. John Nash , . 1 - . Simplexes, - Sperner, Sperner. 3
Sperner , n = 1 n = 2 n . Brouwer Nash - .
6. 1 1.1 1.1. ( ) {x0 , x1 , ..., xn} Rn : n i=0 ixi = 0 n i=0
i = 0 0 = 1 = ... = n = 0 1.2 1.2. E R u, v, E. u v, [u, v] V, [u,
v] = {u + (1 )v/ [0, 1] R}. A E u, v A [u, v] A. . , A E , . 1.3.
P0, P1, ..., Pn Rm m > n v Rm v = n i=0 iPi n i=0 i = 1, i [0,
1]. v = n i=0 iPi n i=0 i = 1, i 0. 1.3 1.3.1 1.1. - : x2 2 + y2 2
1 , A = (x, y) R2 / x2 2 + y2 2 1 . 2
9. 1.1. f : E R . () f (u, ), (v, ) epif. [0, 1] : f(u + (1 )v)
f(u) + (1 )f(v) + (1 ) , (u, ) + (1 )(u, ) epif, f . () epif u, v
E. (u, f(u)), (v, f(v)) f. epif : (u, f(u)) + (1 )(v, f(v)) epif,
[0, 1] : f(u + (1 )v) f(u) + (1 )f(v), [0, 1]. f . 5
10. 2 Simplexes 2.1 n-simplexes. faces, labeling n-simplex
n-Sperner . 2.1.1 n-Simplex 2.1. {P0, P1, ., , , Pn} Rm m > n.
n-simplex Pi, 0 i n n P : n P = n i=0 iPi n i=0 i = 1, i [0, 1]
n-simplex n P {P0, P1, ..., Pn}. , simplex. simplex , n P = [P0,
..., Pn]. {P0, P1, ..., Pn} . 2.1. n-simplex n- . , 0-simplex ,
1-simplex , 2-simplex , 3-simplex ... 2.1.2 Standard n-Simplex 2.2.
Standard n-simplex n-simplex {e1, e2, ..., en+1} Rn+1 . n i=0 iPi,
n i=0 i = 1 n+1 i=1 iei n+1 i=1 i = 1. - standard n-simplex : n S =
y Rn+1 n+1 i=1 yi = 1, yi 0 n-simplex standard n-simplex. 6
11. Simplexes 2.1.3 k-Face n-Simplex 2.3. k n. {V0, ...Vk} {P0,
..., Pn} k-simplex: S k = [V0, ..., Vk] k-face n P. 2.2. 2-simplex,
. 3 3 . 1-faces. 2.3. 3-simplex, . 4 2-faces ( 4 ) 1-faces. : 2.1:
n-simplexes faces . M = n+1 k+1 k-faces n-simplex. 2.4. n-simplex.
(n 1)-face n P facet - : S n1 (i) = [P0, P1, ..., Pi1, Pi+1, ...,
Pn] face n-simplex Pi. 7
12. Simplexes n-simplexes . - , , n-simplexes. n-simplexes n P
n Q . n-simplexes n P = [P0, ..., Pn] n Q = [Q0, ..., Qn] , P0 = Q0
= 0n . P1, ..., Pn Q1, ..., Qn n Rn, . T : Rn Rn : T(Pi) = Qi, i
{1, ..., n} T n-simplexes, . , n-simplexes, n P n. 2.1.4
Symplotopes 2.5. Symplotope n-simplexes. n n ... n. 2.2 Simplicial
2.2.1 n-Simplex 2.6. Simplicial n-simplex n, - n-simplexes n i , i
< : i n i = n , n i , n j n, n i n j , k-face k n. 2.4. n = 2.
2-simplex. . 2-simplex . 0, 1, 2 ( 1-faces), 4 2-simplexes. . 2.3,
, 1-faces. . 0-faces . , labeling, Sperner, . 8
13. Simplexes 2.2: . 2.3: . , n-simplex 0-simplexes ,
0-simplexes . n-simplex n-simplexes, n- simplex. 2.7. y n. y = n
i=0 iPi n i=0 i = 1, [0, 1]. : (y) = {i/i > 0} (y) y. 9
14. Simplexes 2.3 Sperner 2.3.1 Labeling 2.8. K n-simplexes n i
n - simplicial . Labeling K : L : K {1, 2, ..., n + 1} 2.4: simplex
L. - simplexes . 2.3.2 Labeling 2.9. Labeling (proper labeling)
Sperner labeling, labeling : (i) L(Pi) = L(Pj) i = j, Pi, Pj {P0,
..., Pn}. label. (ii) facet S n1 (i) n, Vj S n1 (i), L(Vj) 1, 2,
..., i 1, i + 1, ..., n + 1}. facet i, label i. L(y) (y). labels
{1, 2, ..., n + 1} , Sperner. 2.5. n = 2. 2-simplex. - Sperner.
10
20. Sperner 3.2.3 n- n-, n-simplex - . 1-simplex, n1-simplexes
n-simplexes. - (n 1)-simplex n-simplex n-simplexes. K n-simplex,
Sperner. i n-simplexes . F(i), (0, 1, ..., n 1)-simplexes (n + 1)
i. F(i) : F(i) = 1, (0, 1, ..., n 1, n) simplex 2, (0, 1, ..., n 1,
s) simplex s = {0, 1, ..., n 1} 0, (0, 1, ..., n 2, n 1)-simplex 0
n-simplex . F(i) : i F(i) = 1 [(0, 1, ..., n 1, n) simplexes] + 2
[(0, 1, ..., n 1, 0) simplexes] (3.5) + 2 [(0, 1, ..., n 1, 1)
simplexes] + 2 [(0, 1, ..., n 1, 1) simplexes] + ... + 2 [(0, 1,
..., n 1, n 1) simplexes] : i F(i) = 1 [(0, 1, ..., n 1) simplexes
] + 2 [(0, 1, ..., n 1) simplexes ] (3.6) (n1)-simplex, [(0, 1,
..., n 1) simplexes ] i F(i) = 2Z + 1. (3.5) (3.6) (0, 1, ..., n 1,
n)-simplexes . n . 16
21. 4 Brouwer 4.1 n-simplex 4.1. n-simplex [x0 , x1 , ..., xn]
: Centroid = 1 n + 1 n i=0 xi 4.2 - f : n n. f , z n f(z) = z.
labeling n - simplicial , simplexes f. L labeling. > 0.
simplicial n, n- simplex . labeling L : K {1, ..., n + 1} : v label
: L(v) (v) {i : fi(v) vi} vi i- v fi(v) i- f(v). L(v) label i vi
> 0 f i- v. L (v) {i : fi(v) vi} . . 17
22. Brouwer (v) {i : fi(v) vi} = . , L(v) fi(v) > vi, i (v).
standard simplex n i=0 vi = 1. , vj > 0 j (v), : j(v) vj = n i=0
vi = 1 fj(v) > vj, j (v), : j(v) fj(v) > n i=0 vi = 1 (4.1)
f(v) simplex n. : j(v) fj(v) n i=0 fi(v) = 1 (4.2) (4.1) (4.2) j(v)
fj(v) > 1 j(v) fj(v) 1 . L labeling . 0, simplexes f. L labeling
Sperner, Sperner simplex [0 , 1 , ..., n], fi(j) j i i, j. 0
simplexes. n , . z . j = 0, 1, ..., n, j z 0. f fi(z) zi, i. f(z) =
z, n i=0 fi(z) = 1, n i=0 zi = 1 n i= fi(z) < n i=0 zi, .
Brower. 4.3 Brouwer Symplotopes K = k j=1 nj symplotope f : K K . f
. n = k j=1 nj. K n, f : K K . h : n K . h1 f h : n n , h , h h1 .
f , . Brower z n (h1 f h)(z ) = z . 18
23. Brouwer z = h(z ), z K. : (h1 f)(z) = z = h1 (z) h1 (f(z))
= h1 (z) h1 , f(z) = z. , f. K n. , n j K . - . , n-simplex n ( n +
1 - n ). nj nj K n. K Rn+k n Rn+1 K, n n, Rn, (K) (n) . , K Rn+k n
Rn+1 ( n + k n + 1 n), (K) (n) (K) , (n) . , , n n. standard
2-simplex R3 , - R2 . , standard 1-simplexes R2 . , . 4.1:
symplotope simplex. , (K) (K) (K) (n) . , (K) (n) . . K Rn . K Bn,
Sn1 K ( K). q K. K x x q ( Rn) 19
24. Brouwer 0 K. > 0 B (0) K. x x/ Bn = B1(0) K. 0 K . K ,
x0 0 . K. 0 x0 K x0. B1(0) K K , x0 y B1(0) K. y B1(0) C . x0 , 0
< 1 1 C K. x0 K . f : K Sn1 : f(x) = x |x| f(x) 0 x . f , . K f
. 4.2: . F : Bn K : F(x) = |x|f1 x |x| F f1 . F 0 Sn 0 f1 () K. , F
K. F , . , y K 0. F . 20
25. 5 5.1 Brouwer - . : B, B B[0, 1], B(0, 1). S , S := B = {x
Rn : x, x = 1}. C1 , f : B S , f(x) = x, x S . . f : B B C1 Rn . f
. f(x) x, x B. g : B S , : g(x) , f(x) x, S . g : B S g(x) = x, x S
, . 5.1: g(x) . 21
26. f : B B, . f . - ( Brouwer Symplotopes), - norm Rn. maximum
norm : x := max{|xi|/1 i n} f = (f1, f2, ..., fn). > 0 -
Weierstrass, gi fi(x) gi(x) < x 2. g := (g1, ..., gn) . : f g :=
sup x B f(x) g(x) < g B . : g(x) = g(x) f(x) + f(x) g(x) f(x) +
f(x) < 1 + g : B(0, 1) B(0, 1 + ). h(x) := g(x) 1+ : f(x) h(x) =
f(x) g(x) 1 + = f(x)(1 + ) g(x) 1 + f(x) g(x) + f(x) (1 + f ) 2
f(x) x, x B, , > 0, f(x) x > , x B. g f g < , h , x0 h(x0)
= x0 : > f(x0) g(x0) = f(x0) x0 + x0 g(x0) = (f(x0) x0) + (x0
g(x0)) = f(x0) x0 > . f : B B x0, f(x0) = x0. 22
28. (Game Theory) N n . A = (A1, ..., An), Ai / , - i. a = (a1,
..., an) A . O . : A O u = (u1, ...un), ui : O R ( ) i. 6.2.2 6.8.
(N, (A1, ..., An), 0, , u) X, (X) X. i S i = (Ai). 6.9. Prole prole
, : S = S1 S2 ... S n. si(ai) ai - si. 6.2.3 (Support) 6.10. si i (
) {ai/si(ai) > 0}. . . 6.2.4 6.11. (N, A, u), ui i prole s =
(s1, ..., sn) : ui(s) = aA ui(a) n j=1 sj(aj) 6.2.5 6.12. si = (s1,
..., si1, si+1, ..., sn) prole si i. s = (si, si) 24
29. (Game Theory) prole si - s i S i : ui(s i , si)) ui(si,
si1) si Si. . , . i Si = (Ai). Ai , i , {1, 2, ..., mi} f : f(i) 0,
i mi i=1 f(i) = 1 S i simplex mi , : mi = {x Rm i / mi i=1 xi = 1}
f. , prole S m1 ... mn symplotope 6.3 Nash 6.13. s = (s1, ..., sn)
Nash , i, si si. Nash , prole , . 25
30. 7 Nash-Nash Equilibrium (Nash 1951) prole , - Nash . prole
s S , i N ai Ai : i,ai (s) = max{0, ui(ai, si) ui(s)} i , si si ai.
f : S S f(s) = s , : si(ai) = si(ai) + i,ai (s) biAi si(bi) + i,bi
(s) (7.1) si(ai) = si(ai) + i,ai (s) 1 + biAi i,bi (s) i ai , .
prole s prole s prole s, . f , , si(ai) . si(ai) i,ai (s) , si(ai)
- . i,ai (s) ui(ai, si) ui(s). ui - , . S , symplotope . f f : S S
Brouwer Symplotopes, f . f Nash . 26
31. Nash-Nash Equilibrium () s Nash i,ai = 0, i Nash . :
f(si(ai)) = si(ai) = si(ai) + $$$$X0 i,ai (s) 1 + $$$$$$$X0 biAi
i,bi (s) = si(ai) f(si(ai)) = si(ai) s f. () f, s. f si, ai ui(ai,
s) ui(s). , i,ai (s) = 0 s f, si(ai) = si(ai). (7.1) : si(ai) =
si(ai) + B0 i,ai (s) 1 + biAi i,bi (s) = si(ai) 1 + biAi i,bi (s) :
si(ai) ai si. . i, bi Ai i,bi (s) = 0. , . s Nash . . 27
38. [1] John H. Palmiery, The Brouwer xed point theorem,
Department of Mathematics, University of Washington ACMS seminar
[2] Tara Stuckless, M.Sc. Thesis: Brouwers Fixed Point Theorem:
Methods of Proofs and Generalizations. Simon Fraser University,
March 2003 [3] John M. Lee, Introduction to Topological Manifolds.
Print ISBN: 978-1-4419-7939-1 Publisher: Springer Graduate Texts in
Mathematics Volume 202 2011 [4] Albert Xin Jiang, Kevin
Leyton-Brown A Tutorial on The Proof of the Existence of Nash
Equilibria, Department of Computer Science, University of British
Columbia [5] Warwick Math Organization, Sperners Lemma and Other
Topics In Combinatorial Topology. [6] S. Kumaresan Vector Fields on
Spheres and Brouwers Fixed Point Theorem Dept. of Math. and Stat.
University of Hyderabad Hyderabad 500 046 [7] Vlachopoulou
Athanasia, : Nash . - 2010 34