Romain Abraham

Changing the branching mechanism of a continuous state branching process using immigration (2009)

We construct a continuous state branching process with immigration (CBI) whose immigration depends on the CBI itself and we recover a continuous state branching process (CB). This provides a dual...

A continuum-tree-valued Markov process (2009)

We construct a continuous state branching process with immigration (CBI) whose immigration depends on the CBI itself and we recover a continuous state branching process (CB). This provides a dual...

A continuum-tree-valued Markov process (2009)

We present a construction of a Lévy continuum random tree (CRT) associated with a super-critical continuous state branching process using the so-called exploration process and a Girsanov's theorem....

We present a construction of a Lévy continuum random tree (CRT) associated with a super-critical continuous state branching process using the so-called exploration process and a Girsanov's theorem....

Abraham, Romain, Delmas, Jean-Francois, Voisin, Guillaume

Given a general critical or sub-critical branching mechanism, we define a pruning procedure of the associated Lévy continuum random tree. This pruning procedure is defined by adding some marks on...

Abraham, Romain, Delmas, Jean-Francois, Voisin, Guillaume

Given a general critical or sub-critical branching mechanism, we define a pruning procedure of the associated Lévy continuum random tree. This pruning procedure is defined by adding some marks on...

Pruning a L\'evy continuum random tree (2008)

Abraham, Romain, Delmas, Jean-Francois, Voisin, Guillaume

Given a general critical or sub-critical branching mechanism, we define a pruning procedure of the associated L\'evy continuum random tree. This pruning procedure is defined by adding some marks on...

On the connected components of the support of super Brownian motion and of its exit measure (2008)

Romain Abraham

: Tribe proved in a previous paper that a typical point of the support of super Brownian motion considered at a fixed time is a.s. disconnected from the others when the space dimension is greater...

An active curve approach for tomographic reconstruction of binary radially symmetric objects (2008)

Abraham, Isabelle, Abraham, Romain, Bergounioux, Maitine

This paper deals with a method of tomographic reconstruction of radially symmetric objects from a single radiograph, in order to study the behavior of shocked material. The usual tomographic...

Fragmentation associated with Levy processes using snake (2008)

Fragmentation associated with Levy processes using snake (2008)

We consider the height process of a Levy process with no negative jumps, and its associated continuous tree representation. Using Levy snake tools developed by Duquesne and Le Gall, with an...

An active curve approach for tomographic reconstruction of binary radially symmetric objects (2008)

We consider the height process of a Levy process with no negative jumps, and its associated continuous tree representation. Using Levy snake tools developed by Duquesne and Le Gall, with an...

Abraham, Isabelle, Abraham, Romain, Bergounioux, Maitine

This paper deals with a method of tomographic reconstruction of radially symmetric objects from a single radiograph, in order to study the behavior of shocked material. The usual tomographic...

A penalization approach for tomographic reconstruction of binary axially symmetric objects (2008)

Abraham, Romain, Bergounioux, Maïtine, Trélat, Emmanuel

We propose a variational method for tomographic reconstruction of blurred and noised binary images based on a penalization process of a minimization problem settled in the space of bounded variation...

A penalization approach for tomographic reconstruction of binary axially symmetric objects (2008)

Abraham, Romain, Bergounioux, Maïtine, Trélat, Emmanuel

We propose a variational method for tomographic reconstruction of blurred and noised binary images based on a penalization process of a minimization problem settled in the space of bounded variation...

Abraham, Romain, Delmas, Jean-Francois, Voisin, Guillaume

Given a general critical or sub-critical branching mechanism, we define a pruning procedure of the associated Lévy continuum random tree. This pruning procedure is defined by adding some marks on...

Abraham, Romain, Delmas, Jean-Francois, Voisin, Guillaume

Given a general critical or sub-critical branching mechanism, we define a pruning procedure of the associated Lévy continuum random tree. This pruning procedure is defined by adding some marks on...

Williams' decomposition of the Lévy continuous random tree and simultaneous extinction probability for populations with neutral mutations (2008)

Williams' decomposition of the Lévy continuous random tree and simultaneous extinction probability for populations with neutral mutations (2008)

We consider an initial Eve-population and a population of neutral mutants, such that the total population dies out in finite time. We describe the evolution of the Eve-population and the total...

Avoiding-probabilities for Brownian Snakes and super-Brownian Motion (2007)

We consider an initial Eve-population and a population of neutral mutants, such that the total population dies out in finite time. We describe the evolution of the Eve-population and the total...

Romain Abraham, Romain Abraham, Romain Abraham, Wendelin Werner, Wendelin Werner, Wendelin Werner

Avoiding-probabilities for Brownian snakes and super-Brownian motion

Avoiding-probabilities for Brownian snakes and super-Brownian motion (2007)

Romain Abraham, Wendelin Werner

We investigate the asymptotic behaviour of the probability that a d- dimensional Brownian snake conditioned to survive on a macroscopic scale, avoids 0 when starting at distance " from the...

On States of Exit Measures for Some Superdiffusions : The Critical Case. (2007)

Romain Abraham

. In [9], Sheu studied the states of the exit measure of the (L; ff)- superdiffusion (1 ! ff 2) from a smooth domain of IR d . He proved that the critical dimension is d c = (ff + 1)=(ff \Gamma 1)....

Reflecting Brownian Snake and a Neumann-Dirichlet Problem (2007)

Romain Abraham, Equations Neumann Problem

: The paper deals with a Markov path-valued process : the reflecting Brownian snake. It is a particular case of the path-valued process former introduced by Le Gall. Here the spatial motion (which is...

On States of Exit Measures for Some Superdiffusions : The Critical Case. (2007)

Romain Abraham

. In [9], Sheu studied the states of the exit measure of the (L; fi)- superdiffusion (1 ! fi 2) from a smooth domain of IR d . He proved that the critical dimension is d c = (fi + 1)=(fi \Gamma 1)....

Solutions of Δu = 4u² with Neumann's Conditions Using the Brownian Snake (2007)

Romain Abraham, Jean-francois Delmas

We consider a Brownian snake (Ws ; s 0) with underlying process a reected Brownian motion in a bounded domain D. We construct a continuous additive functional (Ls ; s 0) of the Brownian snake which...

An Active Curve Approach for Tomographic Reconstruction of Binary Radially Symmetric Objects (2007)

Isabelle Abraham, Romain Abraham

This paper deals with a method of tomographic reconstruction from a single radiograph, in order to study the behavior of shocked material. The usual tomographic reconstruction algorithms such as...

Williams' decomposition of the L\'evy continuous random tree and simultaneous extinction probability for populations with neutral mutations (2007)

A penalization approach for tomographic reconstruction of binary axially symmetric objects (2007)

We consider an initial Eve-population and a population of neutral mutants, such that the total population dies out in finite time. We describe the evolution of the Eve-population and the total...

Abraham, Romain, Bergounioux, Maïtine, Trélat, Emmanuel

We propose a variational method for tomographic reconstruction of blurred and noised binary images based on a penalization process of a minimization problem settled in the space of bounded variation...

A penalization approach for tomographic reconstruction of binary axially symmetric objects (2007)

Abraham, Romain, Bergounioux, Maïtine, Trélat, Emmanuel

We propose a variational method for tomographic reconstruction of blurred and noised binary images based on a penalization process of a minimization problem settled in the space of bounded variation...

Strong convergence for urn models with reducible replacement policy (2007)

Abraham, Romain, Dhersin, Jean-Stephane, Ycart, Bernard

A multitype urn scheme with random replacements is considered. Each time a ball is picked, another ball is added, and its type is chosen according to the transition probabilities of a reducible...

Asymptotics for the small fragments of the fragmentation at nodes (2007)

Feller property and infinitesimal generator of the exploration process (2007)

We consider the fragmentation at nodes of the Lévy continuous random tree introduced in a previous paper. In this framework we compute the asymptotic for the number of small fragments at time...

Significant edges in the case of a non-stationary Gaussian noise (2007)

We consider the exploration process associated to the continuous random tree (CRT) built using a Levy process with no negative jumps. This process has been studied by Duquesne, Le Gall and Le Jan....

Abraham, Isabelle, Abraham, Romain, Desolneux, Agnes

In this paper, we propose an edge detection technique based on some local smoothing of the image followed by a statistical hypothesis testing on the gradient. An edge point being defined as a...

Williams' decomposition of the Lévy continuous random tree and simultaneous extinction probability for populations with neutral mutations (2007)

Strong convergence for urn models with reducible replacement policy (2007)

We consider an initial Eve-population and a population of neutral mutants, such that the total population dies out in finite time. We describe the evolution of the Eve-population and the total...

Abraham, Romain, Dhersin, Jean-Stephane, Ycart, Bernard

A multitype urn scheme with random replacements is considered. Each time a ball is picked, another ball is added, and its type is chosen according to the transition probabilities of a reducible...

Significant edges in the case of a non-stationary Gaussian noise (2007)

Abraham, Isabelle, Abraham, Romain, Desolneux, Agnes

In this paper, we propose an edge detection technique based on some local smoothing of the image followed by a statistical hypothesis testing on the gradient. An edge point being defined as a...

Feller property and infinitesimal generator of the exploration process (2007)

Williams' decomposition of the Lévy continuous random tree and simultaneous extinction probability for populations with neutral mutations (2007)

We consider the exploration process associated to the continuous random tree (CRT) built using a Levy process with no negative jumps. This process has been studied by Duquesne, Le Gall and Le Jan....

Asymptotics for the small fragments of the fragmentation at nodes (2007)

We consider an initial Eve-population and a population of neutral mutants, such that the total population dies out in finite time. We describe the evolution of the Eve-population and the total...

Changing the branching mechanism of a continuous state branching process using immigration (2006)

We consider the fragmentation at nodes of the Lévy continuous random tree introduced in a previous paper. In this framework we compute the asymptotic for the number of small fragments at time...

Changing the branching mechanism of a continuous state branching process using immigration (2006)

We construct a continuous state branching process with immigration (CBI) whose immigration depends on the CBI itself and we recover a continuous state branching process (CB). This provides a dual...

Changing the branching mechanism of a continuous state branching process using immigration (2006)

We construct a continuous state branching process with immigration (CBI) whose immigration depends on the CBI itself and we recover a continuous state branching process (CB). This provides a dual...

Changing the branching mechanism of a continuous state branching process using immigration (2006)

We construct a continuous state branching process with immigration (CBI) whose immigration depends on the CBI itself and we recover a continuous state branching process (CB). This provides a dual...

Strong convergence for urn models with reducible replacement policy (2006)

We construct a continuous state branching process with immigration (CBI) whose immigration depends on the CBI itself and we recover a continuous state branching process (CB). This provides a dual...

Abraham, Romain, Dhersin, Jean-Stephane, Ycart, Bernard

A multitype urn scheme with random replacements is considered. Each time a ball is picked, another ball is added, and its type is chosen according to the transition probabilities of a reducible...

Strong convergence for urn models with reducible replacement policy (2006)

Abraham, Romain, Dhersin, Jean-Stephane, Ycart, Bernard

A multitype urn scheme with random replacements is considered. Each time a ball is picked, another ball is added, and its type is chosen according to the transition probabilities of a reducible...

An active curve approach for tomographic reconstruction of binary radially symmetric objects (2006)

Abraham, Isabelle, Abraham, Romain, Bergounioux, Maitine

This paper deals with a method of tomographic reconstruction of radially symmetric objects from a single radiograph, in order to study the behavior of shocked material. The usual tomographic...

An active curve approach for tomographic reconstruction of binary radially symmetric objects (2006)

Abraham, Isabelle, Abraham, Romain, Bergounioux, Maitine

This paper deals with a method of tomographic reconstruction of radially symmetric objects from a single radiograph, in order to study the behavior of shocked material. The usual tomographic...

An active curve approach for tomographic reconstruction of binary radially symmetric objects (2006)

Abraham, Isabelle, Abraham, Romain, Bergounioux, Maitine

This paper deals with a method of tomographic reconstruction of radially symmetric objects from a single radiograph, in order to study the behavior of shocked material. The usual tomographic...

Significant edges in the case of a non-stationary Gaussian noise (2006)

Abraham, Isabelle, Abraham, Romain, Desolneux, Agnes

In this paper, we propose an edge detection technique based on some local smoothing of the image followed by a statistical hypothesis testing on the gradient. An edge point being defined as a...

Significant edges in the case of a non-stationary Gaussian noise (2006)

Abraham, Isabelle, Abraham, Romain, Desolneux, Agnes

In this paper, we propose an edge detection technique based on some local smoothing of the image followed by a statistical hypothesis testing on the gradient. An edge point being defined as a...

Significant edges in the case of a non-stationary Gaussian noise (2006)

Abraham, Isabelle, Abraham, Romain, Desolneux, Agnes

In this paper, we propose an edge detection technique based on some local smoothing of the image followed by a statistical hypothesis testing on the gradient. An edge point being defined as a...

Significant edges in the case of a non-stationary Gaussian noise (2006)

Abraham, Isabelle, Abraham, Romain, Desolneux, Agnes

In this paper, we propose an edge detection technique based on some local smoothing of the image followed by a statistical hypothesis testing on the gradient. An edge point being defined as a...

Asymptotics for the small fragments of the fragmentation at nodes (2006)

Asymptotics for the small fragments of the fragmentation at nodes (2006)

We consider the fragmentation at nodes of the Lévy continuous random tree introduced in a previous paper. In this framework we compute the asymptotic for the number of small fragments at time...

Asymptotics for the small fragments of the fragmentation at nodes (2006)

We consider the fragmentation at nodes of the Lévy continuous random tree introduced in a previous paper. In this framework we compute the asymptotic for the number of small fragments at time...

Forward-backward stochastic differential equations and PDE with gradient dependent second order coefficients (2006)

We consider the fragmentation at nodes of the L\'{e}vy continuous random tree introduced in a previous paper. In this framework we compute the asymptotic for the number of small fragments at time...

Feller property and infinitesimal generator of the exploration process (2006)

We consider a system of fully coupled forward-backward stochastic differential equations. First we generalize the results of Pardoux-Tang concerning the regularity of the solutions with respect to...

Forward-backward stochastic differential equations and PDE with gradient dependent second order coefficients (2006)

We consider the exploration process associated to the continuous random tree (CRT) built using a Levy process with no negative jumps. This process has been studied by Duquesne, Le Gall and Le Jan....

Forward-backward stochastic differential equations and PDE with gradient dependent second order coefficients (2006)

We consider a system of fully coupled forward-backward stochastic differential equations. First we generalize the results of Pardoux-Tang concerning the regularity of the solutions with respect to...

Forward-backward stochastic differential equations and PDE with gradient dependent second order coefficients (2006)

We consider a system of fully coupled forward-backward stochastic differential equations. First we generalize the results of Pardoux-Tang concerning the regularity of the solutions with respect to...

Forward-backward stochastic differential equations and PDE with gradient dependent second order coefficients (2006)

We consider a system of fully coupled forward-backward stochastic differential equations. First we generalize the results of Pardoux-Tang concerning the regularity of the solutions with respect to...

Abraham, Romain, Riviere, Olivier

Feller property and infinitesimal generator of the exploration process (2005)

Feller property and infinitesimal generator of the exploration process (2005)

We consider the exploration process associated to the continuous random tree (CRT) built using a Levy process with no negative jumps. This process has been studied by Duquesne, Le Gall and Le Jan....

Fragmentation associated to Levy processes using snake (2005)

We consider the exploration process associated to the continuous random tree (CRT) built using a Levy process with no negative jumps. This process has been studied by Duquesne, Le Gall and Le Jan....

Fragmentation associated to Levy processes using snake (2005)

We consider the height process of a Levy process with no negative jumps, and its associated continuous tree representation. Using Levy snake tools developed by Duquesne and Le Gall, with an...

Fragmentation associated to Levy processes using snake (2005)

We consider the height process of a Levy process with no negative jumps, and its associated continuous tree representation. Using Levy snake tools developed by Duquesne and Le Gall, with an...

Fragmentation associated to Levy processes using snake (2005)

We consider the height process of a Levy process with no negative jumps, and its associated continuous tree representation. Using Levy snake tools developed by Duquesne and Le Gall, with an...

Solutions of $\Delta u=4 u^2$ with Neumann's conditions using the Brownian snake (2004)

We consider the height process of a Levy process with no negative jumps, and its associated continuous tree representation. Using Levy snake tools developed by Duquesne and Le Gall, with an...

Poisson Snake and Fragmentation (2002)

Abraham, Romain; Université René Descartes (Paris 5); Abraham@math-info.univ-paris5.fr, Serlet, Laurent; Université René Descartes (Paris 5); Serlet@math-info.univ-paris5.fr

Our main object that we call the Poisson snake is a Brownian snake as introduced by Le Gall. This process has values which are trajectories of standard Poisson process stopped at some random finite...

Some properties of the exit measure for super-Brownian motion (2002)