scholarly journals Landau and Grüss type inequalities for inner product type integral transformers in norm ideals

2013 ◽  
pp. 109-125 ◽  
Author(s):  
Danko R. Jocić ◽  
Đ;orđe Krtinić ◽  
Mohammad Sal Moslehian
2020 ◽  
Vol 4 (2) ◽  
pp. 160-169
Author(s):  
Benard Okelo ◽  

In this paper, we give characterizations of certain properties of inner product type integral transformers. We first consider unitarily invariant norms and operator valued functions. We then give results on norm inequalities for inner product type integral transformers in terms of Landau inequality, Grüss inequality. Lastly, we explore some of the applications in quantum theory.


2020 ◽  
Vol 44 (4) ◽  
pp. 571-579
Author(s):  
T. TEIMOURI-AZADBAKHT ◽  
A. G GHAZANFARI

Let X be a Hilbert C∗-module on C∗-algebra A and p ∈ A. We denote by Dp(A,X) the set of all continuous functions f : A → X, which are Fréchet differentiable on a open neighborhood U of p. Then, we introduce some generalized semi-inner products on Dp(A,X), and using them some Grüss type inequalities in semi-inner product C∗-module Dp(A,X) and Dp(A,Xn) are established.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Bin Zheng ◽  
Qinghua Feng

Some new generalizedndimensional Ostrowski type and Grüss type integral inequalities on time scales are established in this paper. The present results unify continuous and discrete analysis, and extend some known results in the literature.


2005 ◽  
Vol 133 (11) ◽  
pp. 3271-3280 ◽  
Author(s):  
Dijana Ilišević ◽  
Sanja Varošanec

Filomat ◽  
2017 ◽  
Vol 31 (2) ◽  
pp. 197-206 ◽  
Author(s):  
Danko Jocic ◽  
Stefan Milosevic ◽  
Vladimir Djuric

If {At}t?? and {Bt}t?? are weakly*-measurable families of bounded Hilbert space operators such that transformers X ??? At*XAtd?(t) and X ??? Bt*XBtd?(t) on B(H) have their spectra contained in the unit disc, then for all bounded operators X ||?AX?B|| ? ||X-?? At* XBtd?(t)||, (1) where ?A def= s-limr?1(I + ??,n=1 r2n ??...??|At1...Atn|2d?n(t1,...,tn)-1/2 and ?B by analogy. If additionally ??,n=1 ??n |A*t1...A*tn|2d?n(t1,...,tn) and ?,n=1 ??n|B*t1...B*tn|2d?n(t1,...,tn) both represent bounded operators, then for all p,q,s > 1 such that 1/q + 1/s = 2/p and for all Schatten p trace class operators X ||?1-1q,A X ?1-1s,B|| ? ||?-1/q,A*(X-?? At* XBtd?(t))?-1/s,B*||p.(2) If at least one of those families consists of bounded commuting normal operators, then (1) holds for all unitarily invariant Q-norms. Applications to the shift operators are also given.


Filomat ◽  
2019 ◽  
Vol 33 (8) ◽  
pp. 2447-2455
Author(s):  
Milan Lazarevic

For a probability measure ? on ? and square integrable (Hilbert space) operator valued functions {A*t}t??, {Bt}t??, we prove Gr?ss-Landau type operator inequality for inner product type transformers |?? AtXBtd?(t)- ?? At d?(t)X ?? Btd?(t)|2? ? ||??AtA*td?(t)- |??A*td?(t)|2||? (?? B*tX*XBtd?(t)- |X?? Btd?(t)|2)?, for all X ? B(H) and for all ? ? [0,1]. Let p ? 2, ? to be a symmetrically norming (s.n.) function, ? (p) to be its p-modification, ? (p)* is a s.n. function adjoint to ?(p) and ||?||?(p)* to be a norm on its associated ideal C?(p)*(H) of compact operators. If X ? C?(p)*(H) and {?n}?n=1 is a sequence in (0,1], such that ??n=1 ?n = 1 and ??n=1 ||?n-1/2 An f||2+||?-1/2n B*nf||2 < +? for some families {An}? n=1 and {Bn}? n=1 of bounded operators on Hilbert space H and for all f ? H, then ||?? n=1 ?-1n AnXBn-?? n=1 AnX ?? n=1 Bn||?(p)* ? ||???n=1 ?-1n |An|2-|??n=1 An|2 X ? ??n=1 ?-1n |B*n|2-|??n=1 B*n|2||?(p)+, if at least one of those operator families consists of mutually commuting normal operators. The related Gr?ss-Landau type ||?||?(p) norm inequalities for inner product type transformers are also provided.


2007 ◽  
Vol 50 (1) ◽  
pp. 23-36 ◽  
Author(s):  
Senka Banić ◽  
Dijana Ilišević ◽  
Sanja Varošanec

AbstractIn this paper we give Bessel- and Grüss-type inequalities in an inner product module over a proper $H^*$-algebra or a $C^*$-algebra.


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