AbstractThe aim of this paper is to establish some results about the existence of multiple solutions for the following singular semipositone boundary value problem of fourth-order differential systems with parameters: $$ \textstyle\begin{cases} u^{(4)}(t)+\beta _{1}u''(t)-\alpha _{1}u(t)=f_{1}(t,u(t),v(t)),\quad 0< t< 1; \\ v^{(4)}(t)+\beta _{2}v''(t)-\alpha _{2}v(t)=f_{2}(t,u(t),v(t)),\quad 0< t< 1; \\ u(0)=u(1)=u''(0)=u''(1)=0; \\ v(0)=v(1)=v''(0)=v''(1)=0, \end{cases} $$
{
u
(
4
)
(
t
)
+
β
1
u
″
(
t
)
−
α
1
u
(
t
)
=
f
1
(
t
,
u
(
t
)
,
v
(
t
)
)
,
0
<
t
<
1
;
v
(
4
)
(
t
)
+
β
2
v
″
(
t
)
−
α
2
v
(
t
)
=
f
2
(
t
,
u
(
t
)
,
v
(
t
)
)
,
0
<
t
<
1
;
u
(
0
)
=
u
(
1
)
=
u
″
(
0
)
=
u
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(
1
)
=
0
;
v
(
0
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=
v
(
1
)
=
v
″
(
0
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=
v
″
(
1
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=
0
,
where $f_{1},f_{2}\in C[(0,1)\times \mathbb{R}^{+}_{0}\times \mathbb{R}, \mathbb{R}]$
f
1
,
f
2
∈
C
[
(
0
,
1
)
×
R
0
+
×
R
,
R
]
, $\mathbb{R}_{0}^{+}=(0,+\infty )$
R
0
+
=
(
0
,
+
∞
)
. By constructing a special cone and applying fixed point index theory, some new existence results of multiple solutions for the considered system are obtained under some suitable assumptions. Finally, an example is worked out to illustrate the main results.
Determination of Fractional Chromatic Numbers in the Operation of Adding Two Different Graphs
