1. A-priori estimates of Carleman's type in domains with boundary Journal des Mathematiques Pures et Appliquees, 73 (1994) 355-387.
  2. Unique continuation for P.D.E's: between Holmgren's theorem and Hormander's theorem, Communications in Partial Differential Equations, 20 (1995), 855-884
  3. Carleman estimates and unique continuation for solutions to boundary-value problems Journal des Mathematiques Pures et Appliques 75, 1996, p 367-408
  4. Carleman estimates, unique continuation and controllability for anizotropic pde's , in Optimization Methods in Partial Diff. Equ., Contemporary Mathematics 209 (AMS), 1997, 267-281
  5. Unique continuation for partial differential operators with partially analytic coefficients. J. Math. Pures Appl. (9) 78 (1999), no. 5, 505--521. This article considers the unique continuation problem for operators whose coefficients depend analytically on some of the variables. The results in here were first proved in [2] above under certain technical assumptions. Part of these assumptions were removed meanwhile by Hormander and Robbiano-Zuily. The goal of this article is to remove the remaining technical assumptions and, at the same time, to considerably simplify the proof of the result.
  6. Uniqueness and Stability in the Cauchy problem for Maxwell and elasticity systems  Nonlinear partial differential equations and their applications. Collège de France Seminar, Vol. XIV (Paris, 1997/1998),  329--349, Stud. Math. Appl., 31. The aim of this article is to show how the methods and results in unique continuation can be applied to Maxwell's equations and to isotropic elasticity. Available in dvi-letter and ps-letter .
  7. On the regularity of boundary traces for the wave equation,  Ann. Scuola Norm. Sup. Pisa Cl. Sci. (4) 26 (1998), no. 1, 185--206. Availlable in dvi-letter , ps-letter format.
  • Carleman estimates, unique continuation and applications This contains some notes on unique continuation and (L2) Carleman estimates. It is fairly long (136 pages) but unfinished, so use it at you own risk :-). In time I plan to revise/complete it, add Lp estimates and, perhaps, put it in a web-friendly format. Available in dvi-letter and ps-letter
  • Carleman estimates and boundary observability for a coupled parabolic-hyperbolic system (joint with Paolo Albano). This paper studies a problem of boundary observability for a coupled system of parabolic-hyperbolic type. First, we prove some Carleman estimates with singular weights for the heat and for the wave equations. Then we combine these results to obtain an observability result for the system.   EJDE Vol. 2000(2000), No. 22, pp. 1-15
  • Null controllability for the dissipative semilinear heat equation. (joint with Sebastian Anita) Appl. Math. Optim.  46  (2002),  no. 2-3, 97--105. No Carleman estimates here, but I didn't find a better place for it. We consider the exact null controllability problem for the semilinear heat equation with a dissipative nonlinearity in a bounded domain of Rn. The main result of the article asserts that if the nonlinearity is even mildly superlinear then global null controllability in arbitrarily short time fails; instead we provide sharp estimates for the controllability time in terms of the size of the initial data. Available in ps-letter .
  • Unique continuation for pde's. The IMA Volumes in Mathematics and its Applications 137, 239-255, 2003. This is a  short expository article whose aim is to provide an overview of the most common types of problems and  results in unique continuation. The $L^2$ Carleman estimates are motivated and discussed in each case. I also tried to track back the origin of the  problems. Available in dvi-letter and ps-letter
  • Strong uniqueness for second order elliptic operators with Gevrey coefficients. (joint with F. Colombini and C. Grammatico) We consider the question of strong unique continuation in Gevrey classes for second order elliptic operators with complex coefficients. The Gevrey index is connected to the angular spread of the range of the principal symbol. Available in pdf-letter.