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Jean Carlo Moraes

Publications and source records attributed to Jean Carlo Moraes.

7 recordsLinked to original sources

On the Structure and Stability of Boundary Mixed Steady States in Evolutionary Games on Networks

We study steady states of evolutionary games on networks in which some players adopt pure strategies while others play mixed strategies. We refer to these configurations as boundary mixed steady states. Such states arise naturally in structured populations and have no counterpart in the classical well-mixed setting. We introduce a relaxed equilibrium notion, called boundary Nash equilibrium, in which the Nash condition is imposed only on non-pure players. In two-strategy systems, this notion characterizes boundary mixed steady states, while this correspondence breaks down in higher dimensions. The stability of these states is governed by the interaction structure among mixed players. When mixed players do not interact, the system exhibits continua of equilibria. In contrast, any nontrivial interaction generically produces instability. In particular, boundary mixed steady states that are not fully degenerate are never asymptotically stable. Degeneracies are further linked to the rank properties of the underlying interaction. These results reveal a structural instability mechanism specific to networked replicator dynamics, highlighting a qualitative gap with respect to the classical well-mixed case and showing how network topology influences the local behavior of equilibria.

math.DS↗

Weighted Inequalities for $t$-Haar multipliers

In this paper, we provide necessary and sufficient conditions on a triple of weights $(u,v,w)$ so that the $t$-Haar multipliers $T^t_{w,σ}$, $t\in \R$, %defined in \cite{P} when $σ=1$, are uniformly (on the choice of signs $σ$) bounded from $L^2(u)$ into $L^2(v)$. These dyadic operators have symbols $s(x,I)=σ_I\,(w(x)/\langle w\rangle_I)^t$ which are functions of the space variable $x\in\R$ and the frequency variable $I\in \mathcal{D}$, making them dyadic analogues of pseudo-differential operators. Here $\mathcal{D}$ denotes the dyadic intervals, $σ_I=\pm1$, and $\langle w\rangle_I$ denotes the integral average of $w$ on $I$. When $w\equiv 1$ we have the martingale transform and our conditions recover the known two-weight necessary and sufficient conditions of Nazarov, Treil and Volberg. %We will discuss some relations between the three weights inequality for these operators given the inequality for other dyadic operators. We also show how these conditions are simplified when $u=v$. In particular, the martingale one-weight and the $t$-Haar multiplier unsigned and unweighted (corresponding to $σ_I\equiv 1$ and $u=v\equiv 1$) known results are recovered or improved. We also obtain necessary and sufficient testing conditions of Sawyer type for the two-weight boundedness of a single variable Haar multiplier similar to those known for the martingale transform.

math.CA↗

Two-weight estimates for the square function and $t$-Haar multipliers

We present necessary and sufficient conditions on triples of weights $(u,v,w)$ for the boundedness of the dyadic weighted square function $S_w$ from $L^2(u)$ into $L^2(v)$. We use this characterization to obtain necessary and sufficient conditions for the boundedness of the $t$-Haar multipliers from $L^2(u)$ into $L^2(v)$ in terms of boundedness of the dyadic weighted square function.

math.CA↗

A Note on the Pure Nash Equilibria for Evolutionary Games on Networks

Recently, a new model extending the standard replicator equation to a finite set of players connected on an arbitrary graph was developed in evolutionary game dynamics. The players are interpreted as subpopulations of multipopulations dynamical game and represented as vertices of the graph, and an edge constitutes the relation among the subpopulations. At each instant, members of connected vertices of the graph play a 2-player game and collect a payoff that determines if the chosen strategies will vanish or flourish. The model describes the game dynamics of a finite set of players connected by a graph emulating the replicator dynamics. It was proved a relation between the stability of the mixed equilibrium with the topology of the network. More specifically, the eigenvalues of the Jacobian matrix of the system evaluated at the mixed steady state are the eigenvalues of the graph's adjacency matrix multiplied by a scalar. This paper studies the pure (strict) Nash equilibria of these games and how it connects to the network. We present necessary and sufficient conditions for a pure steady-state in coordination or anti-coordination game to be a (strict) Nash Equilibrium.

cs.GT↗

On two weight estimates for dyadic operators

We provide a quantitative two weight estimate for the dyadic paraproduct $π_b$ under certain conditions on a pair of weights $(u;v)$ and $b$ in $Carl_{u,v}$, a new class of functions that we show coincides with BMO when $u = v \in A^d_2$. We obtain quantitative two weight estimates for the dyadic square function and the martingale transforms under the assumption that the maximal function is bounded from $L_2(u)$ into $L_2(v)$ and $v \in RH^d_1$. Finally we obtain a quantitative two weight estimate from $L_2(u)$ into $L_2(v)$ for the dyadic square function under the assumption that the pair $(u; v)$ is in joint $A^d_2$ and $u^{-1} \in RH^d_1$, this is sharp in the sense that when $u = v$ the conditions reduce to $u \in A^d_2$ and the estimate is the known linear mixed estimate.

math.FA↗

Weighted estimates for dyadic paraproducts and t-Haar multipiers with complexity (m,n)

We extend the definitions of dyadic paraproduct and t-Haar multipliers to dyadic operators that depend on the complexity (m,n), for m and n positive integers. We will use the ideas developed by Nazarov and Volberg to prove that the weighted L^2(w)-norm of a paraproduct with complexity (m,n) associated to a function b\in BMO, depends linearly on the A_2-characteristic of the weight w, linearly on the BMO-norm of b, and polynomially in the complexity. This argument provides a new proof of the linear bound for the dyadic paraproduct (the one with complexity (0,0)). Also we prove that the L^2-norm of a t-Haar multiplier for any t and weight w depends on the square root of the C_{2t}-characteristic of w times the square root of the A_2-characteristic of w^{2t} and polynomially in the complexity (m,n), recovering a result of Beznosova for the (0,0)-complexity case.

math.CA↗

Sharp bounds for $t$-Haar multipliers on $L^2$

We show that if a weight $w\in C^d_{2t}$ and there is $q >1$ such that $w^{2t}\in A_q^d$, then the $L^2$-norm of the $t$-Haar multiplier of complexity $(m,n)$ associated to $w$ depends on the square root of the $C^d_{2t}$-characteristic of $w$ times the square root $A^d_q$-characteristic of $w^{2t}$ % raised to the power $(p-1)/2$ times a constant that depends polynomially on the complexity. In particular, if $w\in C^d_{2t}\cap A_{\infty}^d$ then $w^{2t}\in A_q^d$ for some $q>1$.

math.FA↗