| This paper is concerned with the construction of a class of positive steady states for a quasi-linear cross-diffusion system describing two-species competition.let r =d1/Ï12, s =1/Ï12,φ= (r + v)u, (?) = v the system(1)can be written asmake the limitÏ12→+∞,Ï12/d1→∞,i.e (s→0+,r→0+)from the first equation of systems(2),we haveφxx→0,if x∈(0, 1),s→0+, r→0+ sinceφ'(x) = 0,x = 0,1 , we haveφ(x)→τ,if x∈(0,1),s→0+,r→0+ make the limit of system(2),we have the shadow system:Chapterâ…¡mainly based on the methods of the calculation of scores and implicit function theorem to find the structure of the shadow system This chapter of the major findings:Theorem: suppose that a1/a2≥1/4 b1/b2+3/4 c1/c2and b1/b21/c2 set up , and d2 issmall enough ,the systems (2) have a spike solution :Chapterâ…¢mainly takes use of perturbation theory return to the non-shadow system equations to find a solutionTheorem: suppose that a1/a2≥1/4 b1/b2+3/4 c1/c2 and b1/b21/c2 set up , there exists smalld0 >0,for each Fixed 0 < d2 < d0 , there exists sufficiently largeα,such that ifα(?)Ï12/d1 >αandÏ12 >α, Equations (1) has a non-constant spike steady state (uα,Ï12(x),uα,Ï12(x)), ifα→∞andÏ12→∞,(uα,Ï12(x),vα,Ï12(x))→(τε/(?)ε(x),(?)ε(x))... |