现在,我们考虑空间\(X=C[0,1]\)使用通常的最大范数
$$\Vert x\Vert=\max_{t\in[0,1]}\bigl\Vert x(t)\bigr\Vert$$
对于任何\((x,y)\以x\乘以x\),标准定义为\(\|(x,y)\|=\max\{\|x\|,\|y\|}\)因此,\((X\乘以X,{\|\cdot\|})\)是巴纳赫空间。我们定义集合P(P)通过
$$\begin{aligned}P=\bigl\{x\ in x:x(t)\geq 0,x(t$$
哪里\(λ=\min\{\alpha-1,\mu-1\}>0\).让\(U=P\乘以P\)显然,U型是一个正常的圆锥体。
Let积分算子\(T:U\到X\乘以X\)由定义
$$\begin{aligned}T(x,y)=\bigl(T_{1}(x,y),T_{2}(x,y)\bigr),\end{alinged}$$
哪里\(T_{1}(x,y)=\int_{0}^{1} G公司_{1} (t,s)f(s,x(s),y(s))\,\mathrm{d} 秒\),\(T_{2}(x,y)=\int_{0}^{1} G公司_{2} (t,s)g(s,x(s),y(s))\,\mathrm{d} 秒\).
根据的定义\(G_{1}(t,s)\)在引理中2.2,因此
$$\begin{aligned}G_{2}(t,s)=\textstyle\begin{cases}\frac{1}{\Gamma(\mu)\Gamma(\Gamma)}[\int_{t}^{1}(\tau-t)^{\mu-1}(\tau-s)^}\Gamma-1}\,\mathrm{d}\tau+(\mu-1)t\int_{s}^{1\tau^{\mu-2}(\ tau-s)\Gamma-1}\,\mathrm{d}\tau],\\quad 0\leqs\leq-t\leq1,\\frac{1}{\Gamma(\mu)\Gamma-(\Gamma)}[\int_{s}^{1}(\tau-t)^{\mu-1}(τ-s)^{γ-1},\mathrm{d}\tau+(\mu-1)t\int_{s}^{1}\tau^{mu-2}(\tau-s){γ-1},\ mathrm}d\tau],\\quad 0\leq-t\leqs\leq1。\结束{cases}\displaystyle\end{aligned}$$
因此,运算符的不动点T型是BVP的解决方案(1.1).
很容易证明
$$\开始{对齐}G_{2}(t,s)\geq 0\quad\text{和}\quad(\mu-1)tA_{2{$$
哪里\(A{2}(s)=\压裂{1}{\伽马(\mu)\Gamma(\Gamma)}\int_{s}^{1}\tau^{\mu-2}(\tau-s)^{\Gamma-1}\,\mathrm{d}\tau\),然后\(\int_{0}^{1} A类_{2} (s)\,\mathrm{d} 秒=\压裂{1}{\伽马(\mu)\Gamma(\Gamma+1)(\mu+\Gamma-1)}:=K_{2}\).
为了证明主要结果,我们需要以下条件:
-
(H1)
\(α+β>2),\(\mu+\gamma>2\);
-
(H2)
\(f(t,x,y)在C中([0,1]\times[0,+\infty)\times[0,+\infty),[0+\inffy)),\(g(t,x,y)在C([0,1]\times[0,+\infty)\times[0,+\infty),[0,++)中).
定理3.1
如果条件(H1)和(H2)持有,操作员 \(T:U\到U\) 是完全连续的.
证明
首先,对于任何\((x,y)\单位为U \),
$$\开始{aligned}&\bigl\VertT_{1}(x,y)\bigr\Vert=\max_{T\in[0,1]}\biggl\Vert\int_{0}^{1} G公司_{1} (t,s)f\bigl(s,x(s),y(s)\bigr)\,\mathrm{d} 秒\biggr\vert\leq\int _{0}^{1} A类_{1} (s)f\bigl(s),x(s)、y(s)\bigr{d} 秒,\\&\开始{对齐}T_{1}(x,y)&=\int_{0}^{1} G公司_{1} (t,s)f\bigl(s,x(s),y(s)\bigr)\,\mathrm{d} 秒\geq(\alpha-1)t\int_{0}^{1} A类_{1} (s)f\bigl(s),x(s)、y(s)\bigr{d} 秒\\&\geq(\alpha-1)t\bigl\Vert t_{1}(x,y)\bigr\Vert\geq\lambda t\bigl\ Vert t_}(x,y)\ bigr\Vert。\end{aligned}\end{alinged}$$
因此,\(T_{1}(x,y)\单位为U \).
同样,我们可以证明\(T_{2}(x,y)\单位为U \)对于任何\((x,y)\单位为U \)显然,操作员\(T:U\到U\).
其次,由于\(G_{1}(t,s)\)和\(G_{2}(t,s)\)和(H2),操作员T型持续打开U型.
让\(U:\|(x,y)\|\leq L\}中的\Omega_{L}=\{(x,y)\)是非空有界闭集,其中\(L>0\)是一个常数。如果\((x,y)在欧米茄{L}中,存在\(M>0)这样的话\(f(t,x,y),\(g(t,x,y))对于任何\((x,y)在欧米茄{L}中,\(在[0,1]\中)因此,我们有
$$\开始{aligned}\bigl\VertT_{1}(x,y)\bigr\Vert=\max_{0\leq-T\leq1}\biggl\Vert\int_{0}^{1} G公司_{1} (t,s)f\bigl(s,x(s),y(s)\bigr)\,\mathrm{d} 秒\biggr\vert\leq M\int_{0}^{1} A类_{1} (s)\,\mathrm{d} 秒=MK_{1}。\结束{对齐}$$
同样,\(T_{2}(x,y).然后,\(T(x,y)\|\leq\max\{MK_{1},MK_2}\})因此,操作员T型一致有界。
第三,对于任何人\((x,y)\单位为U \)和\([0,1]\中的t{1},t{2}\)在不失一般性的情况下,我们假设\(t{1}<t{2})现在,我们证明操作符T型是等连续的。
$$\开始{对齐}&\bigl\vert T_{1}(x,y)(T_{2})-T_{1}(x,y)(T_}1})\bigr\vert\\&\quad=\biggl\vert\int_{0}^{1} G公司_{1} (t{2},s)f\bigl(s,x(s),y(s)\bigr)\,\mathrm{d} 秒-\nint_{0}^{1} G公司_{1} (t_{1},s)f\bigl(s,x(s),y(s)\bigr)\,\mathrm{d} 秒\biggr\vert\\&\quad\leq M\int_{0}^{1}\bigl\vert G_1}(t_{2},s)-G_{1}(t_{1},s)\bigr\vert\,\mathrm{d} 秒\\&\quad=M\biggl[\int_{0}^{t_{1}}\bigl\vert G_{1}(t_{2},s)-G_{1{(t_},s)\bigr\vert\,\mathrm{d} 秒+\nint_{t{1}}^{t{2}}\bigl\vert G{1}{d} 秒\\&\quad\quad{}+\int_{t_{2}}^{1}\bigl\vert G{1}{d} 秒\biggr]\\&\quad=\frac{M}{\Gamma(\alpha)\Gamma(\beta)}\biggl\{\int_0}^{t_{1}}\bigl\vert\biggl[\int_{t_{2}}^{1}(\tau-t{2})^{\alpha-1}(\tau-s){s}^{1}\tau^{\alpha-2}(\tau-s)^{\beta-1}\,\mathrm{d}\tau\biggr]\\&\quad\quad{}-\biggl[\int_{t{1}}^{1}(\tau-t{1})^{α-1}(\tau-s)^{β-1},\mathrm{d}\tau+(\alpha-1)t{1}\int_{s}^{1}\tau^{alpha-2}(\tau-s){d} 秒\\&\quad\quad{}+\int_{t{1}}^{t{2}}\biggl\vert\biggl[\int_}t{2{}^{1}(\tau-t{2})^{alpha-1}(\t au-s)-s)^{β-1}\,\mathrm{d}\tau\biggr]\\&\quad\quad{}-\biggl[\int_{s}^{1}\tau+(\alpha-1)t_{1}\int _{s}^{1}\tau^{\alpha-2}(\tau-s)^{\beta-1}\,\mathrm{d}\tau\biggr]\biggr\vert\,\mathrm{d} 秒\\&\quad\quad{}+\int_{t_{2}}^{1}\biggl\vert\biggl[\int_}s}^{1'(\tau-t{2})^{\alpha-1}(\tau-s)^}\beta-1}\,\mathrm{d}\tau+(\alpha-1)t{2}\int__{s}^}\tau^{alpha-2}(tau-s)\,\mathrm{d}\tau\biggr]\\&\quad\quad{}-\biggl[\int_{s}^{1}t{1}\int_{s}^{1}\tau^{alpha-2}(\tau-s)^{beta-1}\,\mathrm{d}\tau\biggr]\biggr\vert\,\mathr{d} 秒\biggr\}\\&&quad=\frac{M}{\Gamma(\alpha)\Gamma(\beta)}\biggl\{\int _{0}^{1}(\alpha-1)(t_{2} -吨_{1} )\int_{s}^{1}\tau^{alpha-2}(\tau-s)^{beta-1}\,\mathrm{d}\tau\,\mathrm{d} 秒\\&\quad\quad{}+\int_{0}^{t_{1}}\biggl\vert\int_{t_2}}^{1}1}\,\mathrm{d}\tau\biggr\vert\,\mathr{d} 秒\\&\quad\quad{}+\int_{t_1}}^{t_2}}\biggl\vert\int_{t_2}}^}(\tau-t_2})1}\,\mathrm{d}\tau\biggr\vert\,\mathr{d} 秒\\&\quad\quad{}+\int_{t_{2}}^{1}\biggl\vert\int_{s}^{1}\bigl[(\tau-t{2})^{\alpha-1}-(\tau-t{1}){d} 秒\大gr\}\&\quad\leq\frac{M}{\Gamma(\alpha)\Gamma\beta)}\biggl\{(\alpha-1)(t_{2} -吨_{1} )\int_{0}^{1}\,\mathrm{d} 秒\nint_{s}^{1}\tau^{\alpha-2}(\tau-s)^{\beta-1}\,\mathrm{d}\tau\\&\quad\quad{}+\int_{0}^{t{1}}\biggl[\int_t{1{}^{t_2}}(\tau-t{1})tau\\&\quad\quad{}+\int_{t_{2}}^{1}\bigl((\tau-t{1})^{\alpha-1}-(\tau-t{2}),\马特姆{d} 秒\\&\quad\quad{}+\int_{t{1}}^{t{2}}\biggl[\int_}s}^{1}(\tau-t{1')^{alpha-1}(tau-s)}\,\mathrm{d}\tau\biggr]\,\mathrm{d} 秒\\&\quad\quad{}+\int_{t_{2}}^{1}\,\mathrm{d} 秒\nint_{s}^{1}\bigl[(\alpha-1)(\tau-\xi_{1})^{\alpha-2}(t_{2} -吨_{1} )\bigr](\tau-s)^{\beta-1}\,\mathrm{d}\tau\biggr\}\\&\quad\quad\bigl(\mbox{here}\xi_{1}\in(t_{1},t_{2})\biger)\\&\quid\leq\frac{M}{\Gamma_{2} -吨_{1} )\int_{0}^{1}\,\mathrm{d}\tau\int_}^{tau}\tau^{alpha-2}(\tau-s)^{beta-1}\,\ mathrm{d} 秒\\&&\quad\quad{}+\int _{0}^{t_{1}}}\,\mathrm{d} 秒\nint_{t{1}}^{t{2}}(\tau-s)^{beta-1}\,\mathrm{d}\tau+int_{0}^{t1}}\,\ mathrm{d} 秒\nint_{t_{2}}^{1}(\alpha-1)(t_{2} -吨_{1} )(\tau-\xi_{2})^{\alpha-2}(\tau-s)^}\beta-1}\,\mathrm{d}\tau\\&\quad\quad{}+\int_{t{1}}^{t{2}}\,\ mathrm{d} 秒\ int _{s}^{1}(\tau-t{1})^{\alpha-1}(\tau-s)^{\beta-1}\,\mathrm{d}\tau+\ int _{t_{2}}^{1}(\alpha-1)(t_{2} -吨_{1} )\,\mathrm{d} 秒\int_{s}^{1}(\tau-s)^{\alpha+\beta-3}\,\mathrm{d}\tau\biggr\}\\&\quad\quad\bigl_{2} -吨_{1} )\int_{0}^{1}\tau^{\alpha-2}\frac{\tau^{\beta}}{\beta}\,\mathrm{d}\tau\\&\quad\quad{}+int_{0}^{t{1}}(t_{1} -秒)^{\β-1}(t_{2} -吨_{1} )\,\mathrm{d} 秒+(α-1)(t_{2} -吨_{1} )\int_{0}^{t_{1}}\,\mathrm{d} 秒\nint_{t_{2}}^{1}(\tau-\xi_{2})^{alpha+\beta-3}\,\mathrm{d}\tau\\&\quad\quad{}+\int_{t{1}}^}{t{2}{}\,\ mathrm{d} 秒\nint_{s}^{1}(\tau-s)^{beta-1}\,\mathrm{d}\tau+(\alpha-1)(t_{2} -吨_{1} )\int_{t{2}}^{1}\frac{(1-s)^{\alpha+\beta-2}}{\alfa+\beta-2}\,\mathrm{d} 秒\大gr\}\&\quad\leq\frac{M}{\Gamma(\alpha)\Gamma\beta)}\biggl\{(\alpha-1)(t_{2} -吨_{1} )\frac{1}{\beta(\alpha+\beta-1)}+(t_{2} -吨_{1} )\压裂{1}{\β}+(\α-1)(t_{2} -吨_{1} )\frac{1}{\alpha+\beta-2}\\&\quad\quad{}+\int_{t{1}}^{t{2}}\ frac{(1-s)^{beta}}{\beta}\,\mathrm{d} 秒+(吨_{2} -吨_{1} )\压裂{1}{\alpha+\beta-2}\biggr\}\\&\quad\leq\frac{M}{\Gamma(\alpha)\Gamma(\beta)}(t_{2} -吨_{1} )_{2} -吨_{1} ),\quad\mbox{其中}K_{3}=\frac{M}{\Gamma(\alpha)\Gamma(\beta)}\biggl(\frac{3}{\beta}+\frac}2}{\alpha+\beta-2}\bigr)。\结束{对齐}$$
通过(H1),\(K_{3}\)是一个正常数。
同样,对于任何\((x,y)\单位为U \)和\([0,1]\中的t{1},t{2}\),我们有
$$开始{对齐}\bigl\vert T_{2}(x,y)_{2} -吨_{1} ),\quad\text{其中}K_{4}=\压裂{M}{\伽马(\mu)\Gamma(\Gamma)}\biggl(\frac{3}{\Gamma}+\压裂{2}{\mu+\Gamma-2}\bigr)。\结束{对齐}$$
也就是说,操作员T型是等连续的。根据Arzela–Ascoli定理T型是完全连续的。
证明已完成。□
为了方便起见,我们引入了以下符号
$$\开始{对齐}&f_{0}=\lim_{x+y\到0+}\biggl\{\min_{t\in[0,1]}\frac{f(t,x,y)}{x+y}\bigr\},\qquad g_{0{=\lim _{x+y\到0+}\biggl \{\min _{t\in[0,1]{压裂{g(t,x,y){x+y}\bigbr\}、\\&f^{\infty}=\lim_{x+y\to+\infty}\biggl\{max_{t\in[0,1]}\frac{f(t,x,y)}{x+y}\biggr\},\qquad g^{\infty}=\lim_{x+y\to+\ infty{\frac{g(t,x,y)}{x+y}\biggr\},\\&f^{0}=\lim{x+y}to 0+}\biggl\{\max{t\ in[0,1]}\frac{f(t,x,y)}{x+y}\biggr\},\qquad g^{0}=\lim{x+y}to+0}\biggl\{\max{t\ in[0,1]}\frac{g(t,x,y)}{x+y}\biggr\},\\&f_{\infty}=\lim_{x+y\ to+\infty}\bigl\{\min_{t\ in[0,1]}\frac{f(t,x,y)}{x+y}\biggr\},\qquad g_{\infty}=\lim_{x+y\ to+\infty}\biggl\{\min_{t\in[0,1]}\frac{g(t,x,y)}{x+y}\biggr\}。\结束{对齐}$$
引理3.1
假设 \([(\alpha-1){\lambda}K_{1}]^{-1}<f_{0}\leq+\infty\) 和 \([(\mu-1){\lambda}K{2}]^{-1}<g{0}\leq+\infty\) 持有,我们有 \(\|T(x,y)\|\geq\|(x,y)\|\).
证明
案例1。如果\([(α-1){\lambda}K_{1}]^{-1}<f_{0}<+\infty\)和\([(\mu-1){\lambda}K{2}]^{-1}<g{0}<+\infty\)保持,设置\(0<\epsilon_{1}<f_{0}-[(\alpha-1){\lambda}K_{1}]^{-1}\)和\(0<ε{2}<g_{0}-[(\mu-1){\lambda}K_{2}]^{-1}\),存在\(增量{1}>0\)这样的话
$$\开始{aligned}\frac{f(t,x,y)}{x+y}\geqf_{0}-\ε{1},α{g(t,x,y)}{x+y}_{0}-\ε_{2},\quad\text{for all}0<x<\delta _{1},0<y<\delta _{1}。\结束{对齐}$$
那么,我们有
$$\开始{对齐}&f(t,x,y)\geq(f_{0}-\ε{1})(x+y)>\bigl[(alpha-1){\lambda}K{1}\bigr]^{-1}(x+y),\\&g(t,x,y)\geq(g_{0}-\ε{2})(x+y)>\bigl[(\mu-1){\lambda}K{2}\bigr]^{-1}(x+y)。\结束{对齐}$$
案例2。如果\(f_{0}=+\infty\)和\(g{0}=+\infty\),对于两个给定的大数\(N_1}\geq[(\alpha-1){\lambda}K_1}]^{-1}\)和\(N_2}\geq[(\mu-1){\lambda}K_2}]^{-1}\),存在\(增量{2}>0\)这样的话
$$\begin{aligned}\frac{f(t,x,y)}{x+y}\geqN_{1},\qquad\frac{g(t,x,y){x+y}\geq N_{2},\ quad\text{for-all}0<x<delta_{2{,0<y<delta_2}。\结束{对齐}$$
那么,我们有
$$开始{对齐}&f(t,x,y)\geq N_{1}(x+y)\gerq\bigl[(\alpha-1){\lambda}K_{1{\bigr]^{-1}(x+y),\\&g(t,x,y)\ geq N_2}。\结束{对齐}$$
出租\((x,y)\在U\cap\partial\Omega_{r_{1}}\中,其中\(\Omega_{r_{1}}=\{(x,y)\在x\乘以x:\|(x,y)\|\leqr_{1}\}\),\(0<r{1}\leq\min\{delta{1},\delta{2}\}\),我们有
$$\开始{aligned}\bigl\VertT_{1}(x,y)\bigr\Vert&=\max_{T\in[0,1]}\biggl\Vert\int_{0}^{1} G公司_{1} (t,s)f\bigl(s,x(s),y(s)\bigr)\,\mathrm{d} 秒\biggr\vert\\&\geq\max_{t\in[0,1]}\biggl\vert\int_{0}^{1}(\alpha-1)tA_{1}\bigl[(\alfa-1){\lambda}K_{1{1\bigr]^{-1}\bigle(x(s)+y(s)\bigr,\mathrm{d} 秒\biggr\vert\\&\geq\max_{t\in[0,1]}\biggl\vert\int_{0}^{1} t安_{1} (s)[{\lambda}K_{1}]^{-1}\lambda t\bigl(\Vert x\Vert+\Vert y\Vert\bigr)\,\mathrm{d} 秒\biggr\vert\\&\geq K_{1}^{-1}\max_{t\in[0,1]}\biggl\vert t^{2}\int_{0}^{1} A类_{1} (s)\,\mathrm{d} 秒\biggr\vert\cdot\bigl\vert(x,y)\bigr\vert\\&=\bigl\ vert(x,y)\ bigr\ vert。\结束{对齐}$$
同样,\(T_{2}(x,y).
无论上述哪种情况成立,我们都有
$$\bigl\Vert T(x,y)\bigr\Vert=\max_{T\in[0,1]}\bigl\\{bigl\Vert T_{1}(x,y)\biger\Vert,\bigl\ Vert T_{2}(x,y$$
证明已完成。□
备注3.1
要么\([(α-1){\lambda}K_{1}]^{-1}<f_{0}<+\infty\)和\(g{0}=+\infty\)保持或\(f_{0}=+\infty\)和\([(\mu-1){\lambda}K{2}]^{-1}<g{0}<+\infty\)保持,类似于引理3.1,我们也有\(\|T(x,y)\|\geq\|(x,y)\|\).
引理3.2
假设 \(0\leqf^{\infty}<(2K_{1})^{-1}\) 和 \(0\leq g^{\infty}<(2K_{2})^{-1}\) 持有,我们有 \(\|T(x,y)\|\leq\|(x,y)\|\).
证明
案例1。如果\(0<f^{\infty}<(2K_{1})^{-1}\)和\(0<g^{\infty}<(2K_{2})^{-1}\)保持,设置\(0<\增量{3}<(2K{1})^{-1}-f^{\infty}\)和\(0<\delta_{4}<(2K_{2})^{-1}-g^{\infty}\),存在\(N_{3}>0\)这样的话
$$开始{aligned}\frac{f(t,x,y)}{x+y}\leqf^{infty}+delta_{3},\qquad\frac{g(t,x,y){x+y}\leq g^{inffy}+delta_{4},\ quad\text{表示所有}x>N_{3{,y>N_}。\结束{对齐}$$
那么,我们有
$$\begin{aligned}&f(t,x,y)\leq\bigl(f^{\infty}+\ delta _{3}\bigr)(x+y)<(2K_{1})^{-1}(x+y),\\&g(t,x,y)\leq\bigl(g^{\infty}+\ delta _{4}\bigr)(x+y)<(2K_{2})^{-1}(x+y)。\结束{对齐}$$
案例2。如果\(f^{\infty}=0\)和\(g^{\infty}=0\),用于\(\ε{3}\leq(2K{1})^{-1}\)和\(\epsilon_{4}\leq(2K_{2})^{-1}\),存在\(N_{4}>0\)这样的话
$$\begin{aligned}\frac{f(t,x,y)}{x+y}\leq\epsilon_{3},\qquad\frac{g(t,x,y){x+y}\leq \epsilen_{4},\ quad\text{代表所有}x\geq N_{4{,y\geq N_{4]。\结束{对齐}$$
那么,我们有
$$开始{对齐}&f(t,x,y)\leq\epsilon_{3}。\结束{对齐}$$
出租\((x,y)\在U\cap\部分\欧米茄_{R_{1}}中),其中\(\Omega_{R_{1}}=\{(x,y)\在x\乘以x:\|(x,y)\|\leq R_{1}\}\),\(R{1}>\最大\{R{1},N{3},N{4}\}\),我们有
$$\开始{aligned}\bigl\VertT_{1}(x,y)\bigr\Vert&\leq\max_{T\in[0,1]}\biggl\Vert\int_{0}^{1} A类_{1} (s)(2K_{1})^{-1}\bigl(x(s)+y(s)\bigr)\,\mathrm{d} 秒\biggr\vert\\&\leq K_{1}^{-1}\int_{0}^{1} A类_{1} (s)\,\mathrm{d} 秒\cdot\frac{\Vert x\Vert+\Vert y\Vert}{2}\leq\bigl\Vert(x,y)\bigr\Vert。\结束{对齐}$$
同样,\(T_{2}(x,y).
无论上述哪种情况成立,我们都有
$$\bigl\Vert T(x,y)\bigr\Vert=\max_{T\in[0,1]}\bigl\\{bigl\Vert T_{1}(x,y)\biger\Vert,\bigl\ Vert T_{2}(x,y$$
证明已完成。□
备注3.2
要么\(0<f^{\infty}<(2K_{1})^{-1}\)和\(g^{\infty}=0\)保持或\(f^{\infty}=0\)和\(0<g^{\infty}<(2K_{2})^{-1}\)保持,类似于引理3.2,我们也有\(\|T(x,y)\|\leq\|(x,y)\|\).
引理3.3
假设 \(0\leq f ^{0}<(2K_{1})^{-1}\) 和 \(0\leqg^{0}<(2K_{2})^{-1}\) 持有,我们有 \(\|T(x,y)\|\leq\|(x,y)\|\).
证明
案例1。如果\(0<f ^{0}<(2K_{1})^{-1}\)和\(0<g^{0}<(2K_{2})^{-1}\)保持,设置\(0<\ε_{5}<(2K_{1})^{-1}-f^{0}\)和\(0<\epsilon_{6}<(2K_{2})^{-1}-g^{0}\),存在\(δ{5}>0\)这样的话
$$开始{aligned}\frac{f(t,x,y)}{x+y}\leqf^{0}+\epsilon_{5},\qquad\frac{g(t,x,y){x+y}\leq g^{0{+\epsilon_{6},\ quad\text{表示所有}0<x<delta_{5{,0<y<delta_2}。\结束{对齐}$$
那么,我们有
$$开始{对齐}&f(t,x,y)\leq\bigl(f^{0}+\epsilon_{5}\bigr)。\结束{对齐}$$
案例2。如果\(f^{0}=0\)和\(g^{0}=0\),用于\(\epsilon_{7}\leq(2K_{1})^{-1}\)和\(\epsilon_{8}\leq(2K_{2})^{-1}\),存在\(δ{6}>0\)这样的话
$$\begin{aligned}\frac{f(t,x,y)}{x+y}\leq\epsilon_{7},\qquad\frac{g(t,x,y){x+y}\leq \epsilen_{8},\ quad\text{forall}0<x<delta_{6},0<y<delta_{6}。\结束{对齐}$$
那么,我们有
$$开始{对齐}&f(t,x,y)\leq\epsilon_{7}。\结束{对齐}$$
出租\((x,y)\在U\cap\partial\Omega_{r_{2}}\中,其中\(\Omega_{r_{2}}=\{(x,y)\在x\乘以x:\|(x,y)\|\leqr_{2}\}\),\(0<r{2}\leq\min\{delta{5},\delta{6}\}),我们有
$$\开始{aligned}\bigl\VertT_{1}(x,y)\bigr\Vert&\leq\max_{T\in[0,1]}\biggl\Vert\int_{0}^{1} A类_{1} (s)(2K_{1})^{-1}\bigl(x(s)+y(s)\bigr)\,\mathrm{d} 秒\biggr\vert\\&\leq K_{1}^{-1}\int_{0}^{1} A类_{1} (s)\,\mathrm{d} 秒\cdot\frac{\Vert x\Vert+\Vert y\Vert}{2}\leq\bigl\Vert(x,y)\bigr\Vert。\结束{对齐}$$
同样,\(T_{2}(x,y).
无论上述哪种情况成立,我们都有
$$\bigl\Vert T(x,y)\bigr\Vert=\max_{T\in[0,1]}\bigl\\{bigl\Vert T_{1}(x,y)\biger\Vert,\bigl\ Vert T_{2}(x,y$$
证明已完成。□
备注3.3
要么\(0<f ^{0}<(2K_{1})^{-1}\)和\(g^{0}=0\)保持或\(f^{0}=0\)和\(0<g^{0}<(2K_{2})^{-1}\)保持,类似于引理3.3,我们也有\(\|T(x,y)\|\leq\|(x,y)\|\).
引理3.4
假设 \([(α-1){\lambda}K_{1}]^{-1}<f_{\infty}\leq+\infty) 和 \([(\mu-1){\lambda}K{2}]^{-1}<g{\infty}\leq+\infty) 持有,我们有 \(\|T(x,y)\|\geq\|(x,y)\|\).
证明
案例1。如果\([(α-1){\lambda}K_{1}]^{-1}<f_{\infty}<+\infty)和\([(\mu-1){\lambda}K{2}]^{-1}<g{\infty}<+\infty)保持,设置\(0<\delta_{7}<f_{\infty}-[(alpha-1){\lambda}K_{1}]^{-1})和\(0<\delta_{8}<g{\infty}-[(\mu-1){\lambda}K{2}]^{-1}),存在一个常量\(N_{5}>0\)这样的话
$$\begin{aligned}\frac{f(t,x,y)}{x+y}\geq f_{infty}-\delta_{7},\qquad\frac{g(t,x,y){x+y}\geqg{infty}-\delta_{8},\ quad\text{对于任何}x>N_{5},y>N_5}。\结束{对齐}$$
那么,我们有
$$开始{对齐}&f(t,x,y)\geq(f_{\infty}-\delta_{7})1}(x+y)。\结束{对齐}$$
案例2。如果\(f_{0}=+\infty\)和\(g{0}=+\infty\),对于两个常量\(N_{7}\geq[(\alpha-1){\lambda}K_{1}]^{-1}\)和\(N_{8}\geq[(\mu-1){\lambda}K_{2}]^{-1}\),存在一个常量\(N_{6}>0\)这样的话
$$\begin{aligned}\frac{f(t,x,y)}{x+y}\geqN_{7},\qquad\frac{g(t,x,y){x+y}\geq N_{8},\ quad\text{表示任何}x>N_{6},y>N_}6}。\结束{对齐}$$
那么,我们有
$$开始{对齐}&f(t,x,y)\geq N_{7}(x+y)\gerq\bigl[(\alpha-1){\lambda}K_{1}\bigr]^{-1}(x+y),\\&g(t,x,y)\ geq N_{8}。\结束{对齐}$$
出租\((x,y)\在U\cap\partial\Omega_{R_{2}}\中,其中\(\Omega_{R_{2}}=\{(x,y)\在x中\乘以x:\|(x,y)\ | \ leq R_{2}\}\),\(R_{2}>\最大\{R_{2},N_{5},N_{6}\}\),我们有
$$\begin{aligned}\bigl\Vert T_{1}(x,y)\bigr\Vert&\geq\max_{T\in[0,1]}\biggl\Vert\int_{0}^{1}(\alpha-1)tA_1}(s)\bigl[(\alfa-1){\lambda}K_{1}\bigr]^{-1}\bigle(x(s)+y(s)\ bigr)\,\mathrm{d} 秒\biggr\vert\\&\geq\max_{t\in[0,1]}\biggl\vert\int_{0}^{1} t安_{1} (s)[{\lambda}K_{1}]^{-1}\lambda t\bigl(\Vert x\Vert+\Vert y\Vert\bigr)\,\mathrm{d} 秒\biggr\vert\\&\geq K_{1}^{-1}\max_{t\in[0,1]}\biggl\vert t^{2}\int_{0}^{1} A类_{1} (s)\,\mathrm{d} 秒\biggr\vert\cdot\bigl(\vert x\vert+\vert y\vert\bigr)\geq\bigl\vert(x,y)\bigr\vert。\结束{对齐}$$
同样,\(T_{2}(x,y).
无论上述哪种情况成立,我们都有
$$\bigl\Vert T(x,y)\bigr\Vert=\max_{T\in[0,1]}\bigl\\{bigl\Vert T_{1}(x,y)\biger\Vert,\bigl\ Vert T_{2}(x,y$$
证明已完成。□
备注3.4
要么\([(α-1){\lambda}K_{1}]^{-1}<f_{\infty}<+\infty)和\(g_{\infty}=+\infty)保持或\(f_{\infty}=+\infty)和\([(\mu-1){\lambda}K{2}]^{-1}<g{\infty}<+\infty)保持,类似于引理3.4,我们也有\(\|T(x,y)\|\geq\|(x,y)\|\).
定理3.2
假设是这样(H1)和(H2)持有,并且满足以下两个条件之一:
-
(1)
\([(\alpha-1){\lambda}K_{1}]^{-1}<f_{0}\leq+\infty\),\([(\mu-1){\lambda}K{2}]^{-1}<g{0}\leq+\infty\) 和 \(0\leqf^{\infty}<(2K_{1})^{-1}\),\(0\leq g^{\infty}<(2K_{2})^{-1}\);
-
(2)
\(0\leq f ^{0}<(2K_{1})^{-1}\),\(0\leqg^{0}<(2K_{2})^{-1}\) 和 \([(α-1){\lambda}K_{1}]^{-1}<f_{\infty}\leq+\infty),\([(\mu-1){\lambda}K_{2}]^{-1}<g_{\infty}\leq+\infty).
然后,边值问题(1.1)至少有一个正解.
证明
案例1。按引理3.1,对于任何\((x,y)\在U\cap\partial\Omega_{r_{1}}\中,我们有\(\|T(x,y)\|\geq\|(x,y)\|\).通过引理3.2,用于\((x,y)\在U\cap\部分\欧米茄_{R_{1}}中)、和\(r{1}<r{1}\),我们有\(\|T(x,y)\|\leq\|(x,y)\|\).根据引理2.1,边值问题(1.1)至少有一个正解\((x,y)\U \cap(上划线{\Omega}_{R{1}}\diagdown\Omega_{R{1})\).
案例2。按引理3.3,对于任何\((x,y)\在U\cap\partial\Omega_{r_{2}}\中,我们有\(\|T(x,y)\|\leq\|(x,y)\|\).通过引理3.4,用于\((x,y)\在U\cap\partial\Omega_{R_{2}}\中、和\(r{2}<r{2}\),我们有\(\|T(x,y)\|\geq\|(x,y)\|\).根据引理2.1,边值问题(1.1)至少有一个正解\((x,y)\U \cap(上划线{\Omega}_{R{2}}\diagdown\Omega_{R{2})\).
证明已完成。□