TY  - INPR
A1  - Conforti, Giovanni
A1  - Dai Pra, Paolo
A1  - Roelly, Sylvie
T1  - Reciprocal class of jump processes
N2  - Processes having the same bridges as a given reference Markov process constitute its reciprocal class. In this paper we study the reciprocal class of compound Poisson processes whose jumps belong to a finite set A in R^d. We propose a characterization of the reciprocal class as the unique set of probability measures on which a family of time and space transformations induces the same density, expressed in terms of the reciprocal invariants. The geometry of A plays a crucial role in the design of the transformations, and we use tools from discrete geometry to obtain an optimal characterization. We deduce explicit conditions for two Markov jump processes to belong to the same class. Finally, we provide a natural interpretation of the invariants as short-time asymptotics for the probability that the reference process makes a cycle around its current state.
T3  - Preprints des Instituts für Mathematik der Universität Potsdam - 3 (2014) 6 
KW  - reciprocal processes
KW  - stochastic bridges
KW  - jump processes
KW  - compound Poisson processes
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-70776
SN  - 2193-6943
VL  - 3
IS  - 6
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - INPR
A1  - Conforti, Giovanni
A1  - Léonard, Christian
A1  - Murr, Rüdiger
A1  - Roelly, Sylvie
T1  - Bridges of Markov counting processes : reciprocal classes and duality formulas
N2  - Processes having the same bridges are said to belong to the same reciprocal class. In this article we analyze reciprocal classes of Markov counting processes by identifying their reciprocal invariants and we characterize them as the set of counting processes satisfying some duality formula.
T3  - Preprints des Instituts für Mathematik der Universität Potsdam - 3 (2014) 9 
KW  - counting process
KW  - bridge
KW  - reciprocal class
KW  - duality formula
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-71855
SN  - 2193-6943
VL  - 3
IS  - 9
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - INPR
A1  - Dereudre, David
A1  - Roelly, Sylvie
T1  - Path-dependent infinite-dimensional SDE with non-regular drift : an existence result
N2  - We establish in this paper the existence of weak solutions of infinite-dimensional shift invariant stochastic differential equations driven by a Brownian term. The drift function is very general, in the sense that it is supposed to be neither small or continuous, nor Markov. On the initial law we only assume that it admits a finite specific entropy. Our result strongly improves the previous ones obtained for free dynamics with a small perturbative drift. The originality of our method leads in the use of the specific entropy as a tightness tool and on a description of such stochastic differential equation as solution of a variational problem on the path space.
T3  - Preprints des Instituts für Mathematik der Universität Potsdam - 3(2014)11 
KW  - Infinite-dimensional SDE
KW  - non-Markov drift
KW  - non-regular drift
KW  - variational principle
KW  - specific entropy
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-72084
SN  - 2193-6943
VL  - 3
IS  - 11
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  -