7,326 research outputs found
A BSDE-based approach for the optimal reinsurance problem under partial information
We investigate the optimal reinsurance problem under the criterion of
maximizing the expected utility of terminal wealth when the insurance company
has restricted information on the loss process. We propose a risk model with
claim arrival intensity and claim sizes distribution affected by an
unobservable environmental stochastic factor. By filtering techniques (with
marked point process observations), we reduce the original problem to an
equivalent stochastic control problem under full information. Since the
classical Hamilton-Jacobi-Bellman approach does not apply, due to the infinite
dimensionality of the filter, we choose an alternative approach based on
Backward Stochastic Differential Equations (BSDEs). Precisely, we characterize
the value process and the optimal reinsurance strategy in terms of the unique
solution to a BSDE driven by a marked point process.Comment: 30 pages, 3 figure
GKW representation theorem and linear BSDEs under restricted information. An application to risk-minimization
In this paper we provide Galtchouk-Kunita-Watanabe representation results in
the case where there are restrictions on the available information. This allows
to prove existence and uniqueness for linear backward stochastic differential
equations driven by a general c\`adl\`ag martingale under partial information.
Furthermore, we discuss an application to risk-minimization where we extend the
results of F\"ollmer and Sondermann (1986) to the partial information framework
and we show how our result fits in the approach of Schweizer (1994).Comment: 22 page
Detailed analysis of eta production in proton-proton collisions
The check whether the presently available multiresonance coupled channel
analyses can explain the more complex processes is made. The process chosen is
a well measured proces of eta production in proton proton collisions.Comment: 4 pages, talk given at N*2001 Workshop on the Physics of Excited
Nucleons, 2001 Main
Optimal excess-of-loss reinsurance for stochastic factor risk models
We study the optimal excess-of-loss reinsurance problem when both the
intensity of the claims arrival process and the claim size distribution are
influenced by an exogenous stochastic factor. We assume that the insurer's
surplus is governed by a marked point process with dual-predictable projection
affected by an environmental factor and that the insurance company can borrow
and invest money at a constant real-valued risk-free interest rate . Our
model allows for stochastic risk premia, which take into account risk
fluctuations. Using stochastic control theory based on the
Hamilton-Jacobi-Bellman equation, we analyze the optimal reinsurance strategy
under the criterion of maximizing the expected exponential utility of the
terminal wealth. A verification theorem for the value function in terms of
classical solutions of a backward partial differential equation is provided.
Finally, some numerical results are discussed
On a Linearized Problem Arising in the Navier-Stokes Flow of a Free Liquid Jet
In this work, we analyze a Stokes problem arising in the study of the
Navier-Stokes flow of a liquid jet. The analysis is accomplished by showing
that the relevant Stokes operator accounting for a free surface gives rise to a
sectorial operator which generates an analytic semigroup of contractions.
Estimates on solutions are established using Fourier methods. The result
presented is the key ingredient in a local existence and uniqueness proof for
solutions of the full nonlinear problem
The Zakai equation of nonlinear filtering for jump-diffusion observation: existence and uniqueness
This paper is concerned with the nonlinear filtering problem for a general
Markovian partially observed system (X,Y), whose dynamics is modeled by
correlated jump-diffusions having common jump times. At any time t, the
sigma-algebra generated by the observation process Y provides all the available
information about the signal X. The central goal of stochastic filtering is to
characterize the filter which is the conditional distribution of X, given the
observed data. It has been proved in Ceci-Colaneri (2012) that the filter is
the unique probability measure-valued process satisfying a nonlinear stochastic
equation, the so-called Kushner-Stratonovich equation (KS-equation). In this
paper the aim is to describe the filter in terms of the unnormalized filter,
which is solution to a linear stochastic differential equation, called the
Zakai equation. We prove equivalence between strong uniqueness for the solution
to the Kushner Stratonovich equation and strong uniqueness for the solution to
the Zakai one and, as a consequence, we deduce pathwise uniqueness for the
solutions to the Zakai equation by applying the Filtered Martingale Problem
approach (Kurtz-Ocone (1988), Kurtz-Nappo (2011), Ceci-Colaneri (2012)). To
conclude, we discuss some particular cases.Comment: 29 page
Nucleon resonances and processes involving strange particles
An existing single resonance model with S11, P11 and P13 Breit-Wiegner
resonances in the s-channel has been re-applied to the old pi N --> K Lambda
data. It has been shown that the standard set of resonant parameters fails to
reproduce the shape of the differential cross section. The resonance parameter
determination has been repeated retaining the most recent knowledge about the
nucleon resonances. The extracted set of parameters has confirmed the need for
the strong contribution of a P11(1710) resonance. The need for any significant
contribution of the P13 resonance has been eliminated. Assuming that the Baker.
et al data set\cite{Bak78} is a most reliable one, the P11 resonance can not
but be quite narrow. It emerges as a good candidate for the non-strange counter
partner of the established pentaquark anti-decuplet.Comment: 5 pages, 2 figures, contribution to the NSTAR 2004 conference in
Grenobl
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