81,028 research outputs found
Execution and block trade pricing with optimal constant rate of participation
When executing their orders, investors are proposed different strategies by
brokers and investment banks. Most orders are executed using VWAP algorithms.
Other basic execution strategies include POV (also called PVol) -- for
percentage of volume --, IS -- implementation shortfall -- or Target Close. In
this article dedicated to POV strategies, we develop a liquidation model in
which a trader is constrained to liquidate a portfolio with a constant
participation rate to the market. Considering the functional forms commonly
used by practitioners for market impact functions, we obtain a closed-form
expression for the optimal participation rate. Also, we develop a microfounded
risk-liquidity premium that permits to better assess the costs and risks of
execution processes and to give a price to a large block of shares. We also
provide a thorough comparison between IS strategies and POV strategies in terms
of risk-liquidity premium
Neumark Operators and Sharp Reconstructions, the finite dimensional case
A commutative POV measure with real spectrum is characterized by the
existence of a PV measure (the sharp reconstruction of ) with real
spectrum such that can be interpreted as a randomization of . This paper
focuses on the relationships between this characterization of commutative POV
measures and Neumark's extension theorem. In particular, we show that in the
finite dimensional case there exists a relation between the Neumark operator
corresponding to the extension of and the sharp reconstruction of . The
relevance of this result to the theory of non-ideal quantum measurement and to
the definition of unsharpness is analyzed.Comment: 37 page
Localization of Events in Space-Time
The present paper deals with the quantum coordinates of an event in
space-time, individuated by a quantum object. It is known that these
observables cannot be described by self-adjoint operators or by the
corresponding spectral projection-valued measure. We describe them by means of
a positive-operator-valued (POV) measure in the Minkowski space-time,
satisfying a suitable covariance condition with respect to the Poincare' group.
This POV measure determines the probability that a measurement of the
coordinates of the event gives results belonging to a given set in space-time.
We show that this measure must vanish on the vacuum and the one-particle
states, which cannot define any event. We give a general expression for the
Poincare' covariant POV measures. We define the baricentric events, which lie
on the world-line of the centre-of-mass, and we find a simple expression for
the average values of their coordinates. Finally, we discuss the conditions
which permit the determination of the coordinates with an arbitrary accuracy.Comment: 31 pages, latex, no figure
Reflexive Binding and Attitudes de se
In this paper we develop an analysis of reflexive binding involving the reflexive zibun in Japanese. We argue that the reflexive zibun is bound by a POV (point of view) holder that minimally c-commands zibun. The POV holder is defined as an argument (typically subject and Experiencer) that can be a locus of de se belief. Some predicates are incapable of hosting POV holders thus defined in combination with zibun and we call such predicates \u27anti-reflexive\u27 predicates, which are marked as such in the lexicon. De se interpretation plays a key role in both local and long distance binding of zibun
State Determination and Sufficiency of Observables
Informational completeness and the possibility of state distinction and determination are among the more important issues of quantum statistics. We use spectral and semispectral (POV) measures to analyse these questions. For a given W ∗-algebra and a family of normal states on it we investigate the relation between sufficiency in Petz’s sense of a W ∗-subalgebra generated by a spectral measure, and the possibility of determination of these states by means of an observabl
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