# Search results for: K. A. Makarov

Russian Metallurgy (Metally) > 2017 > 2017 > 13 > 1141-1144

Theoretical and Mathematical Physics > 2016 > 186 > 1 > 41-60

_{g}AU*

_{g}= g(A) on Dom(A), where A is a densely defined operator and G ∋ g ↦ U

_{g}is a unitary representation of the subgroup G of the affine group

*G*, the group of affine orientation-preserving transformations of the real axis. If A is a symmetric operator, then the group G induces an action/flow on the operator unit ball of contracting transformations...

Complex Analysis and Operator Theory > 2016 > 10 > 4 > 835-880

Integral Equations and Operator Theory > 2005 > 51 > 1 > 121-140

*A*and

*C*be self-adjoint operators such that the spectrum of

*A*lies in a gap of the spectrum of

*C*and let

*d*> 0 be the distance between the spectra of

*A*and

*C*. Under these assumptions we prove that the best possible value of the constant

*c*in the condition $$\left\| B \right\| < cd$$ guaranteeing the existence of a (bounded) solution to the operator Riccati equation

*XA*−

*CX*+

*XBX*=

*B** is...