On Sidon-Telyakovskii-type conditions for the integrability of multiple trigonometric series
For the trigonometric series $$\sum_{k=0}^{\infty}a_k\sum_{l\in kV \setminus (k-1)V}e^{i(l, x)}, \quad a_k\rightarrow 0,\quad k\rightarrow \infty,$$ given on $[-\pi, \pi)^m$, where $V$ is some polyhedron in $R^m$, we prove that the inequality $$\int\limits_{T^m}\left|\sum^{\infty}_{k=0} a_k \sum_{l\...
Gespeichert in:
| Datum: | 2008 |
|---|---|
| Hauptverfasser: | , , , , , |
| Format: | Artikel |
| Sprache: | Ukrainisch Englisch |
| Veröffentlicht: |
Institute of Mathematics, NAS of Ukraine
2008
|
| Online Zugang: | https://umj.imath.kiev.ua/index.php/umj/article/view/3177 |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| Назва журналу: | Ukrains’kyi Matematychnyi Zhurnal |
| Завантажити файл: | |
Institution
Ukrains’kyi Matematychnyi Zhurnal| _version_ | 1860509221375705088 |
|---|---|
| author | Ivashchuk, O. V. Zaderei, P. V. Pelagenko, E. N. Іващук, О. В. Задерей, П. В. Пелагенко, Є. Н. |
| author_facet | Ivashchuk, O. V. Zaderei, P. V. Pelagenko, E. N. Іващук, О. В. Задерей, П. В. Пелагенко, Є. Н. |
| author_sort | Ivashchuk, O. V. |
| baseUrl_str | https://umj.imath.kiev.ua/index.php/umj/oai |
| collection | OJS |
| datestamp_date | 2020-03-18T19:47:45Z |
| description | For the trigonometric series
$$\sum_{k=0}^{\infty}a_k\sum_{l\in kV \setminus (k-1)V}e^{i(l, x)}, \quad a_k\rightarrow 0,\quad k\rightarrow \infty,$$
given on $[-\pi, \pi)^m$, where $V$ is some polyhedron in $R^m$, we prove that the inequality
$$\int\limits_{T^m}\left|\sum^{\infty}_{k=0} a_k \sum_{l\in kV\setminus(k-1)V}e^{i(l, x)} \right| dx \leq C \sum^{\infty}_{k=0} (k+1) |\Delta A_k|,$$
holds if the coefficients $a_k$ satisfy the following conditions of the Sidon - Telyakovskii type:
$$A_k\rightarrow\infty,\quad |\Delta a_k| \leq A_k, \quad \forall k \geq 0, \quad \sum^{\infty}_{k=0}(k+1) |\Delta A_k| |
| first_indexed | 2026-03-24T02:37:39Z |
| format | Article |
| fulltext |
UDK 517.518.4
P. V. Zaderej, E. N. Pelahenko, O. V. Yvawuk
(Kyev. nac. un-t texnolohyj y dyzajna)
OB USLOVYQX TYPA SYDONA – TELQKOVSKOHO
YNTEHRYRUEMOSTY KRATNÁX
TRYHONOMETRYÇESKYX RQDOV
For the trigonometric series
a ek
k
i l x
l kV k V=
∞
∈ −
∑ ∑
0 1
( , )
\ ( )
, ak → 0, k → ∞ ,
given on [ , )− π π m , where V is some polyhedron in Rm , we prove that the inequality
a e dx C k Ak
k
i l x
l kV k VT
k
km =
∞
∈ − =
∞
∑ ∑∫ ∑≤ +
0 1 0
1( , )
\ ( )
( ) ∆ ,
holds if the coefficients ak satisfy the following conditions of the Sidon – Telyakovskii type:
Ak → 0, ∆a Ak k≤ ∀ ≥k 0, ( )k Ak
k
+ < ∞
=
∞
∑ 1
0
∆ .
Pokazano, wo dlq tryhonometryçnyx rqdiv vyhlqdu
a ek
k
i l x
l kV k V=
∞
∈ −
∑ ∑
0 1
( , )
\ ( )
, ak → 0 , k → ∞ ,
wo zadani na [ , )− π π m , de V — deqkyj poliedr u Rm
, vykonu[t\sq nerivnist\
a e dx C k Ak
k
i l x
l kV k VT
k
km =
∞
∈ − =
∞
∑ ∑∫ ∑≤ +
0 1 0
1( , )
\ ( )
( ) ∆ ,
qkwo koefici[nty ak zadovol\nqgt\ umovy typu Sidona – Telqkovs\koho
Ak → 0 , ∆a Ak k≤ ∀ ≥k 0 , ( )k Ak
k
+ < ∞
=
∞
∑ 1
0
∆ .
Pust\ V — zamknut¥j ohranyçenn¥j polyπdr v R
m
s verßynamy v toçkax s ra-
cyonal\n¥my koordynatamy, zvezdn¥j otnosytel\no naçala koordynat, qvlqg-
wehosq eho vnutrennej toçkoj, y takoj, çto prodolΩenye lgboj eho hrany ne
proxodyt çerez naçalo koordynat; nV = { / }:x R x n Vm∈ ∈ — homotet V. Mno-
Ωestvo polyπdrov s ukazann¥my svojstvamy oboznaçym çerez W.
Pust\ Z
m
— celoçyslennaq reßetka v R
m
.
Oboznaçym çerez L Tm
1( ) prostranstvo opredelenn¥x na T
m
2π -peryodyçe-
skyx yntehryruem¥x funkcyj f ( x ) s normoj
f 1 = f x dx
T m
( )∫ < ∞ ,
© P. V. ZADEREJ, E. N. PELAHENKO, O. V. YVAWUK, 2008
ISSN 1027-3190. Ukr. mat. Ωurn., 2008, t. 60, # 5 579
580 P. V. ZADEREJ, E. N. PELAHENKO, O. V. YVAWUK
hde x = ( x1 , … , xm ) y T
m
= [ – π , π )
m
= [ – π , π )
× … ×
m
��� �� [ – π , π ) .
V dannoj rabote yssleduetsq sxodymost\ kratn¥x tryhonometryçeskyx rq-
dov vyda
a a ek
k
i l x
l kV k V
0
1 1
+
=
∞
∈ −
∑ ∑ ( , )
\ ( )
, (1)
hde x ∈ T
m
, l ∈ Z
m
, ( l, x ) = l x l xm m1 1 + … + , koπffycyent¥ kotor¥x stremqtsq
k nulg pry k → ∞ y udovletvorqgt uslovyqm typa Sydona – Telqkovskoho:
suwestvugt çysla Ak takye, çto
Ak → 0, k → ∞ ,
dlq vsex k ≥ 0
∆ak ≤ Ak , (2)
( )k Ak
k
+
=
∞
∑ 1
0
∆ < ∞ . (3)
Pryvedem nekotor¥e rezul\tat¥, otnosqwyesq k rassmatryvaemoj zadaçe.
V rabote [1] (teoremaGA) ustanovleno, çto esly koπffycyent¥ rqda
a
a kxk
k
0
12
+
=
∞
∑ cos (4)
moΩno predstavyt\ v vyde
ak =
p
m
m
m k
i
i k
m
=
∞
=
∑ ∑α , k = 1, 2, … , (5)
hde αi ≤ 1 y pmm=
∞∑ 1
< ∞ , to rqd (4) qvlqetsq rqdom Fur\e.
S. A. Telqkovskyj v rabote [2] (teoremaG1) prydal uslovyqm (5) bolee udob-
n¥j vyd, a ymenno, pokazal, çto ony πkvyvalentn¥ uslovyqm: ak → 0, k → ∞ ,
y suwestvugt takye çysla Ak , çto
Ak ↓ 0, ∆ak ≤ Ak ∀ k ≥ 0, Ak
k=
∞
∑
0
< ∞ . (6)
Pry πtom poluçena ocenka
a
a kx dxk
k
0
10
2
+
=
∞
∑∫ cos
π
≤ C Ak
k=
∞
∑
0
.
Zdes\ y dalee çerez C budem oboznaçat\ absolgtn¥e poloΩytel\n¥e konstan-
t¥, vozmoΩno, razn¥e v razn¥x formulax.
Krome toho, v [2] (teoremaG2) pokazano, çto dlq rqda
a kxk
k
sin
=
∞
∑
1
, (7)
koπffycyent¥ kotoroho udovletvorqgt uslovyqm (6), ravnomerno otnosytel\-
no p = 1, 2, … spravedlyva ocenka
ISSN 1027-3190. Ukr. mat. Ωurn., 2008, t. 60, # 5
OB USLOVYQX TYPA SYDONA – TELQKOVSKOHO YNTEHRYRUEMOSTY … 581
a kx dxk
k
p
sin
=
∞
+
∑∫
1
1
π
π
=
a
k
O Ak
k
p
k
k= =
∞
∑ ∑+
1 0
.
Pry πtom (7) qvlqetsq rqdom Fur\e v tom y tol\ko v tom sluçae, kohda
a
k
k
k=
∞
∑
1
< ∞ .
Uslovyq (6) naz¥vagt uslovyqmy Sydona – Telqkovskoho.
G. L. Nosenko [3] obobwyl rezul\tat¥ rabot¥ [2] na sluçaj dvojn¥x rqdov
(yz kosynusov, synusov y kosynusov, a takΩe synusov). Sxodymost\ dvojn¥x
tryhonometryçeskyx rqdov v [3] ponymaetsq v sm¥sle Prynshejma.
Obßyrnaq byblyohrafyq, posvqwennaq yntehryruemosty kratn¥x tryhono-
metryçeskyx rqdov, ymeetsq v [4].
V rabote O. Y. Kuznecovoj [5] (teoremaG2.1) dokazano, çto rqd (1), koπffy-
cyent¥ kotoroho udovletvorqgt uslovyqm Sydona – Telqkovskoho (6), sxodyt-
sq poçty vsgdu na T
m
k nekotoroj funkcyy f L Tm∈ 1( ) , qvlqetsq ee rqdom
Fur\e y spravedlyva ocenka
a a e dxk
k
i l x
l kV k VT m
0
1 1
+
=
∞
∈ −
∑ ∑∫ ( , )
\ ( )
≤ C Ak
k=
∞
∑
0
.
Cel\g rabot¥ qvlqetsq dokazatel\stvo sledugwej teorem¥.
Teorema. Pust\ koπffycyent¥ ak rqda (1) stremqtsq k nulg pry k →
→ ∞ y udovletvorqgt uslovyqm (2), (3). Tohda rqd (1) sxodytsq poçty vsgdu
na T
m
k nekotoroj funkcyy f L Tm∈ 1( ) , qvlqetsq ee rqdom Fur\e y spraved-
lyva ocenka
a a e dxk
k
i l x
l kV k VT m
0
1 1
+
=
∞
∈ −
∑ ∑∫ ( , )
\ ( )
≤ C k Ak
k
( )+
=
∞
∑ 1
0
∆ , (8)
a ravenstvo
lim ( )
n
nf S f
→∞
− 1 = 0,
hde
S f xn( , ) = a a ek
k
i l x
l kV k V
0
1 1
+
=
∞
∈ −
∑ ∑ ( , )
\ ( )
— posledovatel\nost\ çastn¥x summ rqda (1), v¥polnqetsq tohda y tol\ko
tohda, kohda
lim ln
n
n
ma n
→∞
= 0. (9)
Zameçanye. V teoreme posledovatel\nost\ { },A kk ≥ 0 stremytsq k nulg
ne obqzatel\no monotonno v otlyçye ot uslovyj (6) y, krome toho, ukazano neob-
xodymoe y dostatoçnoe uslovye sxodymosty v srednem kratn¥x tryhonometry-
çeskyx rqdov vyda (1).
Pry dokazatel\stve budem yspol\zovat\ pryem, predloΩenn¥j S. A. Telq-
kovskym v [6].
ISSN 1027-3190. Ukr. mat. Ωurn., 2008, t. 60, # 5
582 P. V. ZADEREJ, E. N. PELAHENKO, O. V. YVAWUK
PokaΩem snaçala, çto rqd Akk=
∞∑ 0
sxodytsq. Poskol\ku rqd ∆Ajj k=
∞∑
sxodytsq k Ak , to
Ak = ∆Aj
j k=
∞
∑ . (10)
Sledovatel\no, yspol\zuq preobrazovanye Abelq y uslovye (3), naxodym
Ak
k =
∞
∑
0
= ( )k Ak
k
+
=
∞
∑ 1
0
∆ ≤ ( )k Ak
k
+
=
∞
∑ 1
0
∆ < ∞ . (11)
Yz (2) y (11) sleduet, çto
∆ak
k=
∞
∑
0
< ∞ . (12)
Zafyksyruem natural\noe n y k koneçnoj summe
a a ek
k
n
i l x
l kV k V
0
1 1
+
= ∈ −
∑ ∑ ( , )
\ ( )
prymenym preobrazovanye Abelq ( ):a− =1 0 :
a a ek
k
n
i l x
l kV k V
0
1 1
+
= ∈ −
∑ ∑ ( , )
\ ( )
= ∆a D x a D xk kV
k
n
n nV( ) ( )
=
−
∑ +
0
1
,
hde
D xkV ( ) : = ei l x
l kV
( , )
∈
∑
— qdra Dyryxle, sootvetstvugwye mnoΩestvu V.
Poskol\ku posledovatel\nost\ { }( ),D x nnV ≥ 0 ohranyçena poçty vsgdu na
T
m
[5] (lemmaG2.4) y an → 0 pry n → ∞ , dlq poçty vsex x ∈ T
m
ymeet mesto
ravenstvo
a ek
k
i l x
l kV k V=
∞
∈ −
∑ ∑
0 1
( , )
\ ( )
= ∆a D xk kV
k
( )
=
∞
∑
0
, (13)
yz kotoroho, v sylu sxodymosty rqda (12), sleduet sxodymost\ rqda (1) poçty
vsgdu na T
m
. Oboznaçym summu rqda (1) çerez f ( x ) .
Perejdem teper\ k dokazatel\stvu neravenstva (8) y, sledovatel\no, summy-
ruemosty funkcyy f ( x ) .
Zametym, çto dlq vsex k ≥ 0
αk : =
∆a
A
k
k
≤ 1,
poçty dlq vsex x ∈ T
m
y dlq lgboho k ≥ 0
αk kVD x( ) ≤ Cx < ∞ , (14)
hde konstanta Cx zavysyt ot x .
Rassmotrym çastnug summu rqda v pravoj çasty ravenstva (13):
ISSN 1027-3190. Ukr. mat. Ωurn., 2008, t. 60, # 5
OB USLOVYQX TYPA SYDONA – TELQKOVSKOHO YNTEHRYRUEMOSTY … 583
∆a D xk kV
k
n
( )
=
∑
0
= A D xk k kV
k
n
α ( )
=
∑
0
y v¥polnym preobrazovanye Abelq ( ):A− =1 0
∆a D xk kV
k
n
( )
=
∑
0
= ∆A D xk
k
n
j jV
j
k
=
−
=
∑ ∑
0
1
0
α ( ) + A D xn k kV
k
n
α ( )
=
∑
0
: = S S1 2+ .
Yz (14) sleduet, çto dlq poçty vsex x ∈ T
m
αk kV
k
n
D x( )
=
∑
0
≤ C nx( )+ 1 . (15)
Yspol\zuq neravenstvo (15) y sootnoßenye (10), dlq poçty vsex x ∈ T
m
pry
n → ∞ poluçaem
S2 = ∆A D xj
j n
k kV
k
n
=
∞
=
∑ ∑ α ( )
0
≤ C j Ax j
j n
( )+
=
∞
∑ 1 ∆ → 0. (16)
V sylu sxodymosty rqda v pravoj çasty ravenstva (13) y ocenky (16) ymeem
f ( x ) = ∆A D xk
k
j jV
j
k
=
∞
=
∑ ∑
0 0
α ( ). (17)
Yspol\zuq predstavlenye funkcyy (17), a takΩe ocenku [5] (lemmaG2.3)
α j jV
j
k
T
D x dx
m
( )
=
∑∫
0
≤ Ck , (18)
naxodym
f x dx
T m
( )∫ ≤ ∆A D x dxk
k
j jV
j
k
T m=
∞
=
∑ ∑∫
0 0
α ( ) ≤ C k Ak
k
( )+
=
∞
∑ 1
0
∆ .
Ostalos\ pokazat\, çto uslovye (9) qvlqetsq kryteryem sxodymosty rqda (1) v
metryke prostranstva L Tm
1( ).
Prymenqq metod A. N. Kolmohorova [7] dlq dokazatel\stva sxodymosty v
srednem rqda (1), poluçaem
f S fn− ( ) 1 = a e dxk
k n
i l x
l kV k VT m = +
∞
∈ −
∑ ∑∫
1 1
( , )
\ ( )
= ∆a D x a D x dxk kV
k n
n nV
T m
( ) ( )
= +
∞
+∑∫ −
1
1 .
(19)
PokaΩem, çto yntehral ot pervoj summ¥ v poslednem ravenstve (19) stre-
mytsq k nulg pry n → ∞ . V¥polnqq preobrazovanye Abelq y yspol\zuq ocen-
ku (18), naxodym
∆a D x dxk kV
k nT m
( )
= +
∞
∑∫
1
= A D x dxk k kV
k nT m
α ( )
= +
∞
∑∫
1
≤
≤ ∆A D x dx A D x dxk
k n
j jV
j
k
T
n j jV
j
n
Tm m= +
∞
=
+
=
∑ ∑∫ ∑∫+
1 0
1
0
α α( ) ( ) ≤
ISSN 1027-3190. Ukr. mat. Ωurn., 2008, t. 60, # 5
584 P. V. ZADEREJ, E. N. PELAHENKO, O. V. YVAWUK
≤ C k A A nk
k n
n( ) ( )+ + +
= +
∞
+∑ 1 1
1
1∆ ≤
≤ C k A A nk
k n
k
k n
( ) ( )+ + +
= +
∞
= +
∞
∑ ∑1 1
1 1
∆ ∆ → 0 (20)
pry n → ∞ .
Na osnovanyy (20) sootnoßenye (19) moΩno zapysat\ tak:
f S fn− ( ) 1 = a D x dx on nV
T m
+ ∫ +1 1( ) ( ).
Yzvestno [8], çto dlq lgboho polyπdra V suwestvugt konstant¥ C1 y C2
takye, çto
C nm
1 ln ≤ D x dxnV
T m
( )∫ ≤ C nm
2 ln .
Teorema dokazana.
V nastoqwee vremq yzvestn¥ druhye uslovyq yntehryruemosty kratn¥x try-
honometryçeskyx rqdov vyda (1) [9]. Odnako poluçenn¥e v πtoj rabote uslovyq
v nekotor¥x sluçaqx bolee udobn¥ v prymenenyy.
Rassmotrym sledugwyj prymer. Pust\ dlq lgb¥x n, p > 0 takyx, çto
n / p = O ( 1 ) , koπffycyent¥ ak = λk
n( ) , hde
λk
n( ) =
1 0 1
1
1
0 1
, ,
, ,
, .
≤ ≤ − −
− +
+
− ≤ ≤
≥ +
k n p
n k
p
n p k n
k n
V¥berem koπffycyent¥ Ak
n( )
sledugwym obrazom:
Ak
n( ) : = ∆λk
n( ) =
0 0 1
1
1
0 1
, ,
, ,
, .
≤ ≤ − −
+
− ≤ ≤
≥ +
k n p
p
n p k n
k n
(21)
PokaΩem, çto posledovatel\nost\ { }( )Ak
n
k=
∞
0 udovletvorqet uslovyqm teorem¥.
Dejstvytel\no, yz (21) sleduet, çto Ak
n( ) → 0 pry k → ∞ y ∆λk
n( ) ≤ Ak
n( )
dlq vsex k ≥ 0. Proverym v¥polnenye uslovyq (3). Yspol\zuq (21), naxodym
∆Ak
n( ) =
0 0 2
1
1
1
0 1
1
1
0 1
, ,
, ,
, ,
, ,
, .
≤ ≤ − −
−
+
= − −
− ≤ ≤ −
+
=
≥ +
k n p
p
k n p
n p k n
p
k n
k n
Tohda rqd
( ) ( )k Ak
n
k
+
=
∞
∑ 1
0
∆ = 2 1
1
n p
p
− +
+
≤ C
sxodytsq.
ISSN 1027-3190. Ukr. mat. Ωurn., 2008, t. 60, # 5
OB USLOVYQX TYPA SYDONA – TELQKOVSKOHO YNTEHRYRUEMOSTY … 585
Takym obrazom, koπffycyent¥ ak = λk
n( )
udovletvorqgt uslovyqm teo-
rem¥.
Rassmotrym rqd (1) s koπffycyentamy ak = λk
n( )
:
λk
n
k
i l x
l kV k V
e( ) ( , )
\ ( )=
∞
∈ −
∑ ∑
0 1
. (22)
Prymenqq teoremu, poluçaem
λk
n
k
i l x
l kV k VT
e dx
m
( ) ( , )
\ ( )=
∞
∈ −
∑ ∑∫
0 1
≤ C.
Zametym, çto rqd (22) qvlqetsq qdrom porqdka n s yndeksom n – p metoda
summyrovanyq Valle Pussena:
V f xn
n p− ( ; ) = λk
n
k
i l x
l kV k V
e( ) ( , )
\ ( )=
∞
∈ −
∑ ∑
0 1
.
Sledstvye. Dlq lgboj funkcyy f L Tm∈ 1( ) s rqdom Fur\e vyda (1) qdra
Valle Pussena V f xn
n p− ( ; ) porqdka n s yndeksom n – p, hde n, p > 0, n / p =
= O ( 1 ) , ohranyçen¥:
V fn
n p− ( )
1
≤ C.
1. Sidon S. Hinreichende Bedingungen für den Fourier-Charakter einer Trigonometrischen Reihe // J.
London Math. Soc. – 1939. – 14, # 5. – P. 158 – 160.
2. Telqkovskyj S. A. Ob odnom dostatoçnom uslovyy Sydona yntehryruemosty tryhonometry-
çeskyx rqdov // Mat. zametky. – 1973. – 14, # 3. – S.G317 – 328.
3. Nosenko G. L. Ob uslovyqx typa Sydona yntehryruemosty dvojn¥x tryhonometryçeskyx
rqdov // Teoryq funkcyj y otobraΩenyj. – Kyev: Nauk. dumka, 1979. – S.G132 – 149.
4. Zaderej P. V. Ob uslovyqx yntehryruemosty kratn¥x tryhonometryçeskyx rqdov // Ukr.
mat. Ωurn. – 1992. – 44, # 3. – S.G340 – 365.
5. Kuznecova O. Y. Konstant¥ Lebeha y approksymatyvn¥e svojstva lynejn¥x srednyx krat-
n¥x rqdov Fur\e: Dys. … kand. fyz.-mat. nauk. – Doneck, 1985. – 115Gs.
6. Telqkovskyj S. A. Ob uslovyqx yntehryruemosty kratn¥x tryhonometryçeskyx rqdov // Tr.
Mat. yn-ta AN SSSR. – 1983. – 164. – S.G180 – 188.
7. Kolmogorov A. N. Sur l’ordre be grandeur des coefficients de la serie be Fourier – Lebesgue //
Bull. Acad. pol. sci. (A). – 1923. – P. 83 – 86.
8. Podkor¥tov A. N. Porqdok konstant Lebeha summ Fur\e po polyπdram // Vestn. Lenynhr.
un-ta. Mat., mex., astron. – 1982. – 7. – S.G110 – 111.
9. Kuznecova O. Y. Ob odnom klasse N-mern¥x tryhonometryçeskyx rqdov // Mat. zametky. –
1998. – 63, # 3. – S.G402 – 406.
Poluçeno 16.02.07
ISSN 1027-3190. Ukr. mat. Ωurn., 2008, t. 60, # 5
|
| id | umjimathkievua-article-3177 |
| institution | Ukrains’kyi Matematychnyi Zhurnal |
| keywords_txt_mv | keywords |
| language | Ukrainian English |
| last_indexed | 2026-03-24T02:37:39Z |
| publishDate | 2008 |
| publisher | Institute of Mathematics, NAS of Ukraine |
| record_format | ojs |
| resource_txt_mv | umjimathkievua/96/431b835a41f21972b14985ef56ae8296.pdf |
| spelling | umjimathkievua-article-31772020-03-18T19:47:45Z On Sidon-Telyakovskii-type conditions for the integrability of multiple trigonometric series Об условиях типа Сидона - Теляковского интегрируемости кратных тригонометрических рядов Ivashchuk, O. V. Zaderei, P. V. Pelagenko, E. N. Іващук, О. В. Задерей, П. В. Пелагенко, Є. Н. For the trigonometric series $$\sum_{k=0}^{\infty}a_k\sum_{l\in kV \setminus (k-1)V}e^{i(l, x)}, \quad a_k\rightarrow 0,\quad k\rightarrow \infty,$$ given on $[-\pi, \pi)^m$, where $V$ is some polyhedron in $R^m$, we prove that the inequality $$\int\limits_{T^m}\left|\sum^{\infty}_{k=0} a_k \sum_{l\in kV\setminus(k-1)V}e^{i(l, x)} \right| dx \leq C \sum^{\infty}_{k=0} (k+1) |\Delta A_k|,$$ holds if the coefficients $a_k$ satisfy the following conditions of the Sidon - Telyakovskii type: $$A_k\rightarrow\infty,\quad |\Delta a_k| \leq A_k, \quad \forall k \geq 0, \quad \sum^{\infty}_{k=0}(k+1) |\Delta A_k| Показано, що для тригонометричних рядів вигляду $$\sum_{k=0}^{\infty}a_k\sum_{l\in kV \setminus (k-1)V}e^{i(l, x)}, \quad a_k\rightarrow 0,\quad k\rightarrow \infty,$$ що задані на $[-\pi, \pi)^m$ , де $V$ — деякии поліедр у $R^m$ , виконується нерівність $$\int\limits_{T^m}\left|\sum^{\infty}_{k=0} a_k \sum_{l\in kV\setminus(k-1)V}e^{i(l, x)} \right| dx \leq C \sum^{\infty}_{k=0} (k+1) |\Delta A_k|,$$ якщо коефіцієнти $a_k$ задовольняють умови типу Сідона - Теляковського $$A_k\rightarrow\infty,\quad |\Delta a_k| \leq A_k, \quad \forall k \geq 0, \quad \sum^{\infty}_{k=0}(k+1) |\Delta A_k| Institute of Mathematics, NAS of Ukraine 2008-05-25 Article Article application/pdf https://umj.imath.kiev.ua/index.php/umj/article/view/3177 Ukrains’kyi Matematychnyi Zhurnal; Vol. 60 No. 5 (2008); 579–585 Український математичний журнал; Том 60 № 5 (2008); 579–585 1027-3190 uk en https://umj.imath.kiev.ua/index.php/umj/article/view/3177/3101 https://umj.imath.kiev.ua/index.php/umj/article/view/3177/3102 Copyright (c) 2008 Ivashchuk O. V.; Zaderei P. V.; Pelagenko E. N. |
| spellingShingle | Ivashchuk, O. V. Zaderei, P. V. Pelagenko, E. N. Іващук, О. В. Задерей, П. В. Пелагенко, Є. Н. On Sidon-Telyakovskii-type conditions for the integrability of multiple trigonometric series |
| title | On Sidon-Telyakovskii-type conditions for the integrability of multiple trigonometric series |
| title_alt | Об условиях типа Сидона - Теляковского интегрируемости кратных тригонометрических рядов |
| title_full | On Sidon-Telyakovskii-type conditions for the integrability of multiple trigonometric series |
| title_fullStr | On Sidon-Telyakovskii-type conditions for the integrability of multiple trigonometric series |
| title_full_unstemmed | On Sidon-Telyakovskii-type conditions for the integrability of multiple trigonometric series |
| title_short | On Sidon-Telyakovskii-type conditions for the integrability of multiple trigonometric series |
| title_sort | on sidon-telyakovskii-type conditions for the integrability of multiple trigonometric series |
| url | https://umj.imath.kiev.ua/index.php/umj/article/view/3177 |
| work_keys_str_mv | AT ivashchukov onsidontelyakovskiitypeconditionsfortheintegrabilityofmultipletrigonometricseries AT zadereipv onsidontelyakovskiitypeconditionsfortheintegrabilityofmultipletrigonometricseries AT pelagenkoen onsidontelyakovskiitypeconditionsfortheintegrabilityofmultipletrigonometricseries AT ívaŝukov onsidontelyakovskiitypeconditionsfortheintegrabilityofmultipletrigonometricseries AT zaderejpv onsidontelyakovskiitypeconditionsfortheintegrabilityofmultipletrigonometricseries AT pelagenkoên onsidontelyakovskiitypeconditionsfortheintegrabilityofmultipletrigonometricseries AT ivashchukov obusloviâhtipasidonatelâkovskogointegriruemostikratnyhtrigonometričeskihrâdov AT zadereipv obusloviâhtipasidonatelâkovskogointegriruemostikratnyhtrigonometričeskihrâdov AT pelagenkoen obusloviâhtipasidonatelâkovskogointegriruemostikratnyhtrigonometričeskihrâdov AT ívaŝukov obusloviâhtipasidonatelâkovskogointegriruemostikratnyhtrigonometričeskihrâdov AT zaderejpv obusloviâhtipasidonatelâkovskogointegriruemostikratnyhtrigonometričeskihrâdov AT pelagenkoên obusloviâhtipasidonatelâkovskogointegriruemostikratnyhtrigonometričeskihrâdov |