2013; 2(1) : 32-37
Published online February 20, 2013(http:// www.sciencepublishinggroup.com/j/pamj) doi: 10.11648/j.pamj.20130201.15
About solutions of nonlinear algebraic system with two
variables
Rakhshanda Dzhabarzadeh
İnstitute Mathematics and Mechanics of NAN of Azerbaijan, Baku
Email address:
[email protected] (R. Dzhabarzadeh)
To cite this article:
Rakhshanda Dzhabarzadeh. About Solutions of Nonlinear Algebraic System with Two Variables. Pure and Applied Mathematics Journal.
Vol. 2, No. 1, 2013, pp. 32-37. doi: 10.11648/j.pamj.20130201.15
Abstract
:
For nonlinear algebraic system with two variables sufficient conditions of existence of solutions are given. The proof of these statements is received as a corollary of more common reviewing considered in this paper. In particular, in this work the existence of multiple base on eigen and associated vectors of a two parameter system of operators in fi-nite-dimensional spaces is proved. Definitions of the associated vectors, multiple completeness of eigen and associated vectors of two-parameter not selfadjoint systems, nonlinearly depending on spectral parameters are introduced. At the proof of these results we essentially used the notion of the analog of an resultant of two polynomial bundles.Keywords:
Algebraic, Spectral, Resultant, Nonlinear1. Introduction
The spectral theory of operators is one of essential direc-tions of a functional analysis. Many partial equadirec-tions and the equations of mathematical physics, connected with physical processes, demanded the new approach for a solu-tion of these problems.
The method of a separation of variables for a solution of the equations with partial derivatives often appears the most
comprehensible as reduces solution of the complicated
equation with many variables to a solution of system of the ordinary differential equations which research is much easier.
So, for example, with help of multiparameter theory problems of a quantum mechanics [7,15,16], theories of a
diffraction[9,10], theories of elastic envelopes, calculation
of nuclear reactors [14], equilibrium processes of diffusion type [13], a Brownian motion [13], boundary value prob-lems for the equations of elliptic-parabolic type, a Cauchy problem for the ultra parabolic equations [11], etc. are solved.
Despite of an urgency and prescription of these re-searches, the spectral theory of multiparameter systems is studied insufficiently. Available outcomes in this area until recently are obtained only for multiparameter selfadjoint systems of the operators linearly depending on spectral parameters.
The founder of researches of spectral problems of the multiparameter selfadjoint systems was F.V. Atkinson [1]. Studied the outcomes which are available for multipara-meter symmetrical differential systems, Atkinson has con-structed the spectral theory of selfadjoint multiparameter systems in finite-dimensional spaces. Further, by means of passage to the limit Atkinson has generalized the received outcomes on a case of multiparameter systems with the selfadjoint compact operators in infinite-dimensional Hil-bert spaces.
In the further, it has appeared possible to build the con-struction of Atkinson in infinite-dimensional spaces. It has allowed construct the spectral theory of multiparameter systems in Hilbert spaces [3, 8] with help a design intro-duced by Atkinson for study of multiparameter systems in finite-dimensional spaces,
But, unfortunately, the technique of research in these works essentially uses only selfadjoint operators entering into multiparameter system of operators. For not selfadjoint multiparameter systems the investigated technique does not allow to solve the simplest problems of the spectral theory
of operators.
The author offers the new approach to research of mul-tiparameter problems.
vectors are introduced.
2. Multiparameter Spectral Theory and
Its Application to Nonlinear
Alge-braic System
For the statement of existence of a solution of
1 1 1
1 1 `1 1
0 1 1
( , )
...
...
0
+ +
= +
+ +
+
+ +
=
m n n
m m m n
a x y
a
a x
a x
a
y
µ
a
y
(1)2 2 2
2 `2 2
0 1 1
( , )
...
...
0
+ +
=
+
+
+
+
+
+
=
m m n
m m n
b x y
b
b x
b
x
b
y
b
y
we essentially use outcomes of author concerning the multiparameter systems, published in works [4-6] .
In the given article the multiply base property of system of eigen and associated vectors of two parameter system
1 1 1
1 `1 1
m
0 1 m
n
m 1 m n
A( , )x
(A
A
...
A
A
+...
A
+)x
0
λ µ =
+ λ + + λ
+µ
+ + µ
=
(2)2 2 2
2 `2 2
m
0 1 m
n
m 1 m n
B( , )y
(B
B
...
B
B
+...
B
+)y
0
λ µ =
+ λ + + λ
+µ
+ + µ
=
is investigated.
Below we shall reduce these outcomes as they have in-dependent meanings. is established in tensor product
2 1
H
H
⊗
of finite-dimensional spacesH
1 andH2Dimension of space His the product of dimensions of
spaces
H
1 and H2 . In (2) linear operators)
,...,
1
,
0
(
i
m
1n
1A
i=
+
act in finite-dimensional spaceH
1;and linear operators
B
i(
i
=
0
,
1
,...,
m
2+
n
2)
act infi-nite-dimensional space
H
2.If f1⊗ f2∈H1⊗H2 and g1⊗g2∈H1⊗H2 then
in-ner product of these elements in space H1⊗H2 is defined
by means of the formulae[f1⊗f2,g1⊗g2]H1⊗H2=
( )
f1,g1H1⋅(g1,g2)H2This definition is spread to other elements of tensor product spaces on linearity.
Let's reduce a series of known positions concerning the spectral theory of multiparameter system.
Definition1. ([1, 3])
(
λ
,
µ
)
∈
C
2 is an eigen value of thesystem (2) if there are nonzero elements
x
∈
H y
1,
∈
H
2such that (2) is fulfilled. A tensor z=x⊗y is named an
eigenvector of system (2).
Definition2. An operator
A
k=
A
k⊗
E
2+
(accordingly,
k
k E B
B+= 1⊗ ) where
E
1 (accordingly,E2) is identicaloperators in
H
1(accordingly,H
2), names operator, inducedin
H
=
H
1⊗
H
2by operatorsA
k (accordingly,Bk).Definition3.[5] A tensor
z
m1,m2 name(
m
1,
m
2)
- theas-sociated vector to an eigenvector
z
0,0=
x
⊗
y
iffollow-ing conditions are satisfied
µ
λ
λ
2µ
1 2 1
)
,
(
!
!
1
0 2 1
r r r r k
r
A
r
r
i
i
∂
∂
∂
+ + ≤≤
∑
z
k1−r1,k2−r2=
0
µ λ
µ λ
2 1 2 1 ( , )
! ! 1 , 0
2 1
r r r r k r
A r r
i ∂ ∂
∂+ + ≤
≤
∑
0
2 2 1
1−r,k −r
=
k
z
(3).
2
,
1
;
2
,
1
;
=
=
≤
m
i
s
k
s s(
k1,k2)
is arrangement from set of the whole nonnegativenumbers on 2 with possible recurring and zero.
Definition4. Systems of elements
{ }
x,1 (k 1,2,...,n)r
k
k = of
finite-dimensional space H1⊗H2 form
n
-fold base inthis space if any
n
of elements f1,...,fnof spaceH
1⊗
H
2can be spread out in series ( 1,..., )
1 ,
n i x c
f s
k k ki
i=
∑
== with
coefficients, not dependent on an index of vectorsf1,...,fn.
If systems
{ }
, 1( 1, 2,..., )r k i k
x i n
= = are constructed on
{ }
r k k x,1 =1
with by the certain rules, equalities ( 1,..., )
1 ,
n i x c
f s
k k ki
i=∑ =
=
mean existence of
n
-fold base on system of eigen andassociated vectors of the system (2).
Definition5.[5]. Let be two polynomial bundles
m m
A
A
A
A
(
λ
)
=
0+
λ
1+
...
+
λ
,
n n
B
B
B
B
(
λ
)
=
0+
λ
1+
...
+
λ
,(4)
depending on the same parameter
λ
and acting,gener-ally speaking, in various Hilbert spaces
H
1,
H
2, accordingly.The operatorRes(A(
λ
),B(λ
)) is under construction
⋅⋅ ⋅ ⋅⋅
⋅
⋅ ⋅⋅ ⋅ ⋅ ⋅ ⋅⋅ ⋅ ⋅ ⋅ ⋅
⋅⋅ ⋅ ⋅⋅
⋅
⋅⋅ ⋅ ⋅⋅
⋅
⋅⋅ ⋅ ⋅⋅
⋅
⋅ ⋅⋅ ⋅ ⋅ ⋅ ⋅⋅ ⋅ ⋅ ⋅ ⋅
⋅⋅ ⋅ ⋅⋅
⋅
⋅⋅ ⋅ ⋅⋅
⋅
⊗ =
+ + + +
+ +
− +
+
+ +
+ +
+ + + +
+ +
− +
+
+ +
+ +
n n m
n
m m m
m
B B B B
B B B
B
B B
B B
A A A A
A A A
A
A A
A A
B A s
2 1 0
1 1
0 2 1 0
2 1 0
1 1
0 2 1 0
0 0 0
0 0
0 0 0
0 0
0 0
0 0
)) ( , ) ( (
Re λ λ (5)
in [2,17] names abstract analog of an Resultant for po-lynomial bundles (4).
In definition of a Resultant (5) of bundles (4) lines with
operators Airepeated
n
of times, and lines with оperatorsi
B
repeated exactlym
of times.m
,n
there are thehighest orders of parameter
λ
in bundles of)
(
λ
A
,(B(λ)), accordingly. Thus, the Resultant is anoper-ator, acting in space m n
H
H
⊗
)
+n
m
+
of copies of tensor product spacesH
1⊗
H
2.
Value of
Re
s
(
A
(
λ
)
,
B
(
λ
))
is equal to its formal expansionwhen each term of this expansion is tensor product of
op-erators. Let operator
A
m, orB
n, is invertible. If the highestorders of parameter
λ
in bundles of A(λ
)andB
(
λ
)
coincide (see [17]) or if the highest orders of parameter
λ
in bundles of A(λ) andB(λ)), generally speaking, can not
coincide (see [2]) bundles (4) have a common point of spectra in the only case when the Resultant of these bundles has nonzero kernel. It is natural, that in case of when bun-dles act in finite-dimensional spaces, this common point of spectra of these bundles is a common eigen value of these bundles.
Theorem. Let operators
A
i(
i
=
0
,
1
,...,
m
1+
n
1)
also) ,..., 1 , 0
(i m2 n2
Bi = + act in finite-dimensional spaces
1
H
and2
H
, accordingly, and one of three following conditions isfulfilled:
a)
max(
m
1n
2,
m
2n
1)
=
m
1n
2,{ }
θ
=
{ }
θ
=
2+ 21
,
m nm
KerB
KerA
;2 2 1
,
m nm
B
A
+ are selfadjoint operators everyone in theirspace
b)
max(
m
1n
2,
m
2n
1)
=
m
2n
1,{ }
θ
=
{ }
θ
=
1+12
,
m nm
KerA
KerB
operators
B
m2A
m1+n1are selfadjoint everyone in theirspaces
c)
m
1n
2=
m
2n
1,{ }
2 1 1 2 2 1
1 2 2 1 1 2
( mn mn n ( 1)n n mn n mn )
Ker A ⊗B + + − A + ⊗B = θ ,
2 2 1 1 2
1
,
m,
m n,
m nm
B
A
B
A
+ + are the selfadjoint operators, actingeveryone in its finite-dimensional space.
Then themax(m1n2,m2n1)-fold base on system of eigen
and associated vectors of (4) takes place.
Proof. It is fixed one of parameters in (4). For a
deter-minacy, we shall suppose, that it is parameter
λ
and0 λ
λ= .Then it is received two bundles, each of which
de-pends on one parameter
µ
.
1 `1
1 1 `1 1
0 0 0 1
m n
0 m m 1 m n
A(
, )
A
A
...
A
A
+...
A
+λ µ =
+ λ
+ +
λ
+ µ
+ + µ
2 2
2 2 `2 2
0 0 0 1
m n
0 m m 1 m n
B(
, )
B
B
...
B
B
+...
B
+λ µ =
+ λ
+ +
λ
+ µ
+ + µ
(6)We introduce labels
1 1 0 1 0 0
0
)
...
(
~
m mA
A
A
A
λ
=
+
λ
+
+
λ
,2 2 0 1 0 0
0
)
...
(
~
m mB
B
B
B
λ
=
+
λ
+
+
λ
Then an Resultant of bundles
1 1 ` 1 ` 1
...
)
(
~
)
,
(
0 0 1 n m nm
A
A
A
A
λ
µ
=
λ
+
µ
++
+
µ
+2 2 ` 2 2
...
)
(
~
)
,
(
0 0 1 m nn
m
B
B
B
B
λ
µ
=
λ
+
µ
++
+
µ
+ ,depending on one parameter
µ
looks like: ⋅⋅ ⋅ ⋅⋅ ⋅ ⋅ ⋅⋅ ⋅ ⋅ ⋅ ⋅⋅ ⋅ ⋅ ⋅ ⋅ ⋅⋅ ⋅ ⋅⋅ ⋅ ⋅⋅ ⋅ ⋅⋅ ⋅ ⋅⋅ ⋅ ⋅⋅ ⋅ ⋅ ⋅⋅ ⋅ ⋅ ⋅ ⋅⋅ ⋅ ⋅ ⋅ ⋅ ⋅⋅ ⋅ ⋅⋅ ⋅ ⋅⋅ ⋅ ⋅⋅ ⋅ ⊗ = = + + + + + + + + + + − + + + + + + + + + + + + + + + + + + + + + − + + + + + + + + + + + 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 0 1 1 0 2 1 0 2 1 0 1 1 0 2 1 0 0 0 ) ( ~ 0 0 0 0 ) ( ~ 0 0 0 ) ( ~ ( ) ~ 0 0 0 0 ) ( ~ 0 0 0 ) ( ~ )) , ( , ) , ( ( Re n m m m n m n m m n m m m n m m m n m n m m n m m m B B B B B B B B B B B B A A A A A A A A A A A A B A s λ λ λ λ λ λ µ λ µ λ (7)
In (7) lines with operators
A
iare repeatedn2of times, andlines with operators Biare repeated
n
1 of times. Thus, theResultant
Re
s
(
A
(
λ
0,
µ
),
B
(
λ
0,
µ
))
is an operator inspace
(
)
1 22 1
n n
H
H
⊗
+ that there is a direct sumn
1+
n
2 ofcopies of tensor product spaces
H
1⊗
H
2.
From outcomes of work [2] follow, that spectra of oper-ators 1 1 ` 1 ` 1 1 1 ... ... ) ,
( 0 0 0 1 0 1 m n
n m m m A A A A A
Aλ µ = +λ + +λ +µ + + +µ + ,
2 2 ` 2 2 2 2 ... ... ) ,
( 0 0 0 1 0 1 m n
n m m m B B B B B
B
λ
µ
= +λ
+ +λ
+µ
+ + +µ
+intersect if and only if
KerR
(
A
(
λ
0),
B
(
λ
o))
≠
{ }
θ
.As operators A( , ), ( , )
λ µ
Bλ µ
act in finite-dimensionalspaces this common point of their spectra can be only common eigen value of these bundles. The last means, that
the two parameter system (2) has an eigen value(λ0,µ0(λ0)). If
the element 1 2
2
1 ) ( )
~ ,..., ~ , ~
( 1 2 1 2
n n n
n H H
x x x
z= + ∈ ⊗ + belongs to
the kernel of an Resultant Res(A(λ0,µ),B(λ0,µ)), then
0
~
~
...
~
~
~
)
(
~
1 1 1 11 21
0
+
+
+
=
+ + + + + n n m
m
x
A
x
A
x
A
λ
0
~
~
...
~
~
~
)
(
~
1 3 1 20
+
1+
+
1 1 1+=
+ + + + + n n m
m
x
A
x
A
x
A
λ
0
~
~
...
~
~
~
)
(
~
2 1 1 1 2 12 1 1
0
+
+
+
+=
+ + + + + + n n n m n m
n
A
x
A
x
x
A
λ
0
~
~
...
~
~
~
)
(
~
2 2 2 2 1 21
0
+
+
+
=
+ + + + + n n m m
x
B
x
B
x
B
λ
(8)0
~
~
...
~
~
~
)
(
~
1 3 1 20
+
2+
+
2 2 2+=
+ + + + + n n m m
x
B
x
B
x
B
λ
0
~
~
...
~
~
~
)
(
~
2 1 2 2 1 21 1 1
0
+
+
+
+=
+ + + + + + n n n m n m
n
B
x
B
x
x
B
λ
By sequential elimination of elements 1 21 1 2
~x H H
n
2 1 2
~ H H
x ∈ ⊗ from system of equalities (8), we come to
some equation in tensor product spaceH1⊗H2. To the similar
equation we come by representation of value of Resultant ).
, ( , ) ( (
Res A λ0 B λ0
By virtue of bulkiness of the received equation
opera-tional coefficients at degrees
λ
i we shall designatethrough
C
~
i(
i
=
1
,
2
,...,
max(
m
1n
2,
m
2n
1))
.Let's introduce a label
max(
m
1n
2,
m
2n
1)
=
r
.Thus, wecome to some equation
0 ~ ~ ... ~ ~ ~ ~ ~ ) ( ~
1 0 1 1 0 1 0 1
0 x =Cx + Cx+ + Cx =
C r
r
λ λ
λ , acting in a tensor
product space
2 1
H
H
H
=
⊗
. As the parameterλ
isfixed arbitrarily, we consider a bundle
0
~
~
...
~
~
~
~
~
)
(
~
1 1
1 1 0
1
=
C
x
+
C
x
+
+
C
x
=
x
C
rr
λ
λ
λ
(9)in finite-dimensional space
H
=
H
1⊗
H
2.From outcomes of the spectral theory of operators fol-lows, that the received bundle (9) in finite-dimensional
space has
r
-fold base on system of its eigen andasso-ciated vectors. Really, at realization of conditions Theorem are satisfied all conditions of the Theorem of Keldysh [12], concerning multiply completeness of system of eigen and associated vectors of polynomial bundle
r r
C C C
C~(
λ
)=~0+λ
~1+...+λ
~The theorem of Keldysh is following: let
T
nisselfad-joint completely continuous operator of the finite order (
T
n∈
σ
p),KerTn={ }
θ , operators ( =0,1,..., −1)−
n i
T
T n
i n
i
com-pletely continuous operators then
n
-fold completeness ofsystem of eigen and associated vectors of the operational
bundle n
n
T T
T
T(λ)= 0+λ 1+...+λ ,acting in a Hilbert space,
takes place.
Let's remind, that under an eigen value of a polynomial
bundleT(λ) such the complex number
0
λ
is understood,that for it exists such nonzero vector
0
x
, thatT
(
λ
0)
x
0=
x
0,m
-th associated vectork
x
to an eigenvector0
x
is thevector, satisfying to conditions
k 0 k 0 k 1
k
0 0 k
d
x T ( ) x T ( ) x d
1 d
. . . T ( ) x ; k 1, . . . , m k ! d
−
= λ + λ
λ
+ + λ =
λ
Let
{ }
xk,0 be a system of eigen and associated vectors of abundleT(
λ
),then derivative systems of vectors on systemof eigen and associated vectors of polynomial bundle
)
(
λ
T
are constructed by rules0
j t
i,0 j
i, j i
i 1,0 0,0 t 0
d
e (x
dt x
t t
x ... x
1! i!
λ
−
=
+
=
+ +
,... 2 , 1 = i
In case of finite-dimensional space all conditions of the Theorem of Keldysh
are fulfilled ,consequently, system of eigen and
asso-ciated vectors of a bundle r
rC
C C
C~(λ)=~0+λ~1+...+λ~ forms
r
-fold base in space H1⊗H2.Really, at realization of a conditions a) of the Theorem
coefficient at
λ
ris an operatorr
C
~
= 1 2 2 2 1n n m n m B
A ⊗ + . It is easy
to see, that it is selfadjoint operator and ( ⊗ +)=
{ }
θ
1 2 2 2 1
n n m n
m B
A
Ker ;
At realization of conditions b) of the Theorem it is had,
that + ⊗ =
{ }
θ1 2 2
1 1
n m n
n
m B
KerA , operator 1
2 2
1 1
n m n
n
m B
A + ⊗ is selfadjoint,
and, at last, at realization of conditions c) of the Theorem
the operator 2 1 1 2
1 1 2 ( 1)
n n n n m n m
A + ⊗B + − 1
2 2
1 1
n m n
n m
B
A
+⊗
is selfadjointand 1
2 2
1 1
( n
m n
n
m B
A
Ker + ⊗ 1 2 2 1
{ }
1 2 2
( 1)
n n n n)
m m n
A
B
+θ
+ −
⊗
=
also.In all these three cases at coefficient at
λ
rof bundle)
(
~
0
λ
C
is selfadjoint invertible operator.Remains to prove concurrence of system of eigen and associated vectors of a two-parameter problem (2) and systems of eigen and associated vectors of the polynomial bundle (9) received by the above-stated way in tensor
product spaceH1⊗H2.
Let
x
~
be an eigenvector of the equation (9). Supposingx
x
~
~
1
=
and using that fact, that (9) there is an expansion ofa Resultant (4), we determine vectors
~
,
2
x
~
x
3,...,
~
x
n1+n2.Besides from (8) it is had, that an element
(
~
,
~
,
2 1
x
x
~
x
3,...,
2 1 2
1
)
(
)
~
2 1
n n n
n
H
H
x
+∈
⊗
+ enters into the kernel of a Resultant)) , ( , ) , ( (
Res A
λ
0µ
Bλ
0µ
of bundles A(λ0,µ)andB(λ0,µ).In works [5, 6] the subsequent components of the
ele-ment
(
~
x
1,
~
x
2,
,...,
~
3x
~ )2 1n
n
x+ entering into the kernel of
Re-sultant
Re
s
(
A
(
λ
0)
,
B
(
λ
0))
are for the first time wellenough studied . In particularities, in case of when opera-tional bundles act in finite-dimensional space and depend on the same parameters, the aspect of the first component
1
~
x
of the element(
~
x
1,
~
x
2,
~x3,...,2 1 2
1
)
(
)
~
2 1
n n n
n
H
H
x
+∈
⊗
+,enter-ing into the kernel of a Resultant Res(A(
λ
0,µ
),B(λ
0,µ
)) isconstructed by the following manner :
1
~
x
has the formlinear combinations of elements
, ... 0 1 1
0 i i
i V U V U V
U⊗ + −⊗ + + ⊗ where
U
0,...,
U
i(accordingly,i
V
V0,..., ) is a restricted chain of eigen and associated vectors
of the bundle
A
(
λ
0,
µ
)
(accordingly, B(λ0,µ)) at thefixed value of parameter
λ
=
λ
0. The parameterµ
, beingsome common eigen value
µ
(
λ
0)
both of operators)
,
(
λ
0µ
A
andB(λ0,µ).m
U
U
0,...,
(accordingly,s
V
V
0,...,
) system of eigen and associated vectors of anoperator
A
(
λ
0,
µ
)
(accordingly, B(λ0,µ)), ad equatingto their common eigen value
µ
(
λ
0)
.,
~
,
~
(
x
1x
2,...,
~
3
x
~ )2 1n
n
x+ coincide with the elements of
deriva-tive systems constructed on the first components
. ... 0 1 1
0 i i
i V U V U V
U ⊗ + − ⊗ + + ⊗ Eigen values
(
λ
0,
µ
(
λ
0))
of twoparameter system (2) can be several and all they
have in the first coordinate number
λ
0.The form of the first component of element entering the kernel of the resultant of a two polynomial bundles from one parameter acting in finite-dimensional spaces is an-nounced in [2]. For two-parameter systems in Hilbert spaces, at realization of some conditions the aspect of the first coordinate
~
x
1 of an element (~x1,~x2,,...,
~
3
x
2 1 2
1 ) ( )
~
2 1
n n n
n H H
x +
+ ∈ ⊗ , entering into the kernel of a Resultant
)) , ( , ) , ( (
ResAλ0 µ Bλ0 µ is announced in [5].
We shall show, that each eigenvector of the equation 0
~ ) ( ~
0 x =
C λ is the first component of an element, entering
into the kernel of Resultant of bundlesA(λ0,µ)andB(
λ
0,µ
).Really, considering
~
x
=
~
x
1, we have that the left part of theequation
C
~
(
λ
0)
~
x
=
0
represents expansion of aResul-tant (7) on a vector
~
x
.Converting to definition of eigen and associated vectors of two-parameter system, from (9) we discover, that the
element 1
~ ~ x
x= can be an eigenvector of two-parameter
system of operators (3), ad equating to an eigen value ))
( ,
(λ0 µ λ0 or the associated vector of this system (3) ad
equating to some eigen value
(
λ
0,
µ
(
λ
0))
in whichdefini-tion there is no derivadefini-tion on the parameter
λ
.Such associated vectors of two-parameter system would be expedient for naming the associated vectors of
two-parameter system in a direction
µ
. Similarly,asso-ciated vectors in which definition there is no derivation on
parameter
µ
, we shall name the associated vectors oftwo-parameter system in a direction
λ
.
Thus, all eigenvectors of the equation (9) corresponding
to eigen value
0
λ
are either eigen vector or associatedvector on direction
µ
of the twoparameter systemcor-responding to an eigen value(λ0,µ(λ0)).
Remains to prove, that all associated vectors of (9) also be the associated vectors of a two-parameter problem (2).
Let
1
~
y
there is a first associated vector to aneigenvec-tor
1
~
x
of the equation (9)corresponding to its eigen value
0
λ
. Then we have
0 1 0 1 r 0 0 0 1 r
r 1
1 1 0 r 1 1 2 2 1
d C( )y C( )x
d
(C C ... C )y
C x ... r −C x , (max(m n , m n ) r)
λ + λ
λ
= + λ + + λ +
+ + + λ =
ɶ ɶ ɶ ɶ ɶ ɶ ɶ ɶ ɶ ɶ ɶ ɶ
(10)
and
0
~
~
...
~
~
~
~
~
)
(
~
1 0 1
1 0 1 0 1
0
x
=
C
x
+
C
x
+
+
C
x
=
C
λ
λ
λ
r r (11)Equation (11) means that there is nonzero element
2 1 2 1
)
~
,...,
~
,
~
(
1 2 n nn n
H
x
x
x
+∈
+ , entering into the kernel ofRe-sultant of bundles
1 1 ` 1 ` 1
1 1
...
...
)
,
(
0 0 0 1 0 1 m nn m
m m
A
A
A
A
A
A
λ
µ
=
+
λ
+
+
λ
+
µ
++
+
µ
+ ,2 2 ` 2 2
2 2
...
...
)
,
(
0 0 0 1 0 1 m nn m
m m
B
B
B
B
B
B
λ
µ
=
+
λ
+
+
λ
+
µ
++
+
µ
+such that (8) is fulfilled.
It is clear that all eigen vectors of (6) coincide with the 1-st component of element from the KerRe ( (s Aλ µ0, ), (Bλ µ0, )).We
have the completeness of eigen and associated vectors of the
)) , ( , ) , ( (
Res Aλ0 µ Bλ0 µ in space
2 1
)
(
1 2n n
H
H
⊗
+If
(
1 22 1
)
~
,...,
~
,
~
(
~
2 1
n n n n
H
y
y
y
y
=
+∈
+ the 1-st associatedvector to eigen vector 1 2
2 1 )
~ ,..., ~ , ~ ( 1 2
n n n
n H
x x
x + ∈ + of the
opera-torRes(A(λ0,µ),B(λ0,µ))then we have that the following
expressions (12) and equalities (8) are fulfilled
1
1 1 1
0 1 m 1 2
m n n 0 1
A (
)y
A
y
...
d
A
y
A(
)x
0
d
+ +
+
+ +
λ
+
+ +
+
λ
=
λ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
1
1 1 1
0 2 m 1 3
m n n 1 0 2
A ( )y
A
y
...
d
A
y
A( )x
0
d
+ +
+
+ + +
λ
+
+ +
+
λ
=
λ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
2 1 2
1 1 1 2 2
0 n m 1 n 1
m n n n 0 n
A ( )y
A
y
...
d
A
y
A( )x
0
d
+ +
+ +
+ + +
λ
+
+ +
+
λ
=
λ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
(12)2
2 2 2
0 1 m 1 2
m n n 0 1
B (
)y
B
y
...
d
B
y
B(
)x
0
d
+ +
+
+ +
λ
+
+ +
+
λ
=
λ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
1 2 1
2 2 1 2 1
0 n m 1 n 1
m n n n 0 n
B (
) y
B
y
...
d
B
y
B(
)x
0
d
+ + +
+ +
+
+ +
λ
+
+ +
+
λ
=
λ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
ɶ
1 1 1 1
0 1 m 1 2 m n n
A (
ɶ
+λ
)x
ɶ
+
A
ɶ
+ +x
ɶ
+ +
... A
ɶ
+ +x
ɶ
=
0
(13)0
~
~
...
~
~
~
)
(
~
2 1 1 1 2
1
2 1 1 1
0
+
+
+
+=
+ + +
+ + +
+
n n n m n
m
n
A
x
A
x
x
1 2 2 2 0 1 m 1 2 m n n
B (
+λ
)x
ɶ
+
B
ɶ
+ +x
ɶ
+ +
... B
ɶ
+ +x
ɶ
=
0
0
~
~
...
~
~
~
)
(
2 1 2 2 1
2
1 2 1
0
+
+
+
+=
+ + +
+ + +
n n n m n
n
n
B
x
B
x
x
B
λ
The last means, that
1
~
y
there is the associated vector oftwo-parameter system corresponding to eigenvector
1
~
x
with eigen value(
λ
0,µ
(λ
0)). From (8) we obtain (11). From(12) and (13) we obtain (10).By analogy in the image it is possible to prove, that the associated vectors of other orders
of the equations (9) corresponding to an eigen value
λ
0also are the associated vectors of two-parameter system (2).
At each eigen value
λ
0 of the equation (9) correspondingto
λ
0 eigen and associate vectors of (9) coincide with eigenand associated vectors of the two-parameter system (2),
corresponding some eigen values (λ0,µ(λ0))of system (2) .
Eigen vector of the equation (9) is eigenvector of (2) or its
associated vector on direction
µ
.
Associated vectors of theequation (9),corresponding to eigen value
λ
0are alsoas-sociated vectors of the system (2). Earlier we proved that the system of all eigen and associated vectors of the
equa-tion (9) forms the max(m1n2,m2n1)-fold base of space
.
2 1H
H
⊗
Then the system of eigen and associated vectorsof two-parameter system (2) also forms max(m1n2,m2n1)
-fold base in spaceH1⊗H2. The Theorem is proved.
In the special case, whenH1 = H2 = R and operators
1 1 2 2
, , ( 1, 2 , ..., ; 1, 2 , ..., )
i k
A B i = m + n k = m + n are
real numbers.
If to consider variables
x
andy
parameters then thealgebraic system (1) is a special case of multiparameter system (2).
Corollary. Let one of three following conditions is ful-filled:
a)
max(
m
1n
2,
m
2n
1)
=
m
1n
2, am1≠0,bm2+n2≠0;b)max(m1n2,m2n1)=m2n1,
b
m2≠
0 ,
a
m1+n1≠
0
c)
m
1n
2=
m
2n
1 is 2 1 1 2 2 11 1 2 ( 1) 1 2 2 0,
n n n n n n m n m m m n
a + b + − a b + ≠
Then the algebraic system (1) has the solutions.
3. Conclusion
In this paper it is proved the existence of solutions of some nonlinear algebraic system .For the proof of this it is essentially used the results of author, obtained for the mul-tiparameter system of operator in the finite dimensional
spaces
References
[1] Atkinson F.V. Multiparameter spectral theory. Bull.Amer.Math.Soc.1968, 74, 1-27
[2] Balinskii A.I Generation of notions of Bezutiant and Re-sultant DAN of Ukr SSR, ser.ph.-math and tech. of sciences,1980, 2, pp.3-6( in Russian).
[3] Browne P.J. Multiparameter spectral theory. Indiana Univ. Math. J,24, 3, 1974.
[4] Dzhabarzadeh R.M. On existence of common eigen value of some operator-bundles, that depends polynomial on para-meter. International conference of topology, 3-9 oct., 1987, Baku. Tez., part 2,page 99
[5] Dzhabarzadeh R.M. Spectral theory of two parameter system in finite dimensional space. Transactions of Azerbaijan Na-tional Academy of Sciences, v.XVIII,3-4,pp.12-18
[6] Dzhabarzadeh R.M. Multiparameter spectral theory. Lam-bert Academic Publishing , 2 mart 2012, pp.182
[7] Prugoveĉku E. Quantum mechanics in Hilbert space. Aca-demic Press, New York, London, 1971
[8] Sleeman B.D. Multiparameter spectral theory in Hilbert space. Pitnam Press, London, 1978, pp.118.
[9] Hargrave B.A., Sleeman B.D. The numerical solution of two-parameter eigenvalue to the problem of diffraction by a plane angular sector. J. Inst.Math. Applic.14, 1974, 9-22. [10] Voytovich N.N., Katsenelenbaum B.Z., Sivov A.N.Generaliz
a method of characteristic oscillations in the theory of a dif-fraction - М.: publishing "Science", 1977. - pp. 416. [11] Genchev Т.Q. (Генчев) About the ultraparabolic equations.
DAS of USSR, 1963, т.151, №2, p.265-268 (in Russian) [12] Keldysh М.V. About completeness of eigenfunctions of
some classes of self-conjugate linear operators. UMN, 1971, т.27, issue 4, p.15-41.(in Russian)
[13] Levi P. (Леви). Stochastic processes and a Brownian motion. М.: publishing "Science", 1979, pp 375 (in Russian). [14] MarchukG.I. (Марчук) . Metody of calculation of nuclear
reactors. М.: , "State Atom Publishing",1961 (in Russian). [15] Richmakher R (Рихмахер). Printsipy of modern
mathemat-ical physics., M. publishing "Mir", 1982,p. 486 (in Russian). [16] Fok V.A. (Фок). The beqinnings of a quantum mechanics. М.:
Publishing "Science", 1976, pp,376.