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Continuous pluriharmonic boundary values

Per Åhag, Rafał Czyż (2007)

Annales Polonici Mathematici

Let D j be a bounded hyperconvex domain in n j and set D = D × × D s , j=1,...,s, s≥ 3. Also let ₙ be the symmetrized polydisc in ℂⁿ, n ≥ 3. We characterize those real-valued continuous functions defined on the boundary of D or ₙ which can be extended to the inside to a pluriharmonic function. As an application a complete characterization of the compliant functions is obtained.

Convergence and uniqueness problems for Dirichlet forms on fractals

Roberto Peirone (2000)

Bollettino dell'Unione Matematica Italiana

M 1 è un particolare operatore di minimizzazione per forme di Dirichlet definite su un sottoinsieme finito di un frattale K che è, in un certo senso, una sorta di frontiera di K . Viene talvolta chiamato mappa di rinormalizzazione ed è stato usato per definire su K un analogo del funzionale u grad u 2 e un moto Browniano. In questo lavoro si provano alcuni risultati sull'unicità dell'autoforma (rispetto a M 1 ), e sulla convergenza dell'iterata di M 1 rinormalizzata. Questi risultati sono collegati con l'unicità...

Convexity of sublevel sets of plurisubharmonic extremal functions

Finnur Lárusson, Patrice Lassere, Ragnar Sigurdsson (1998)

Annales Polonici Mathematici

Let X be a convex domain in ℂⁿ and let E be a convex subset of X. The relative extremal function u E , X for E in X is the supremum of the class of plurisubharmonic functions v ≤ 0 on X with v ≤ -1 on E. We show that if E is either open or compact, then the sublevel sets of u E , X are convex. The proof uses the theory of envelopes of disc functionals and a new result on Blaschke products.

Cramér's formula for Heisenberg manifolds

Mahta Khosravi, John A. Toth (2005)

Annales de l'institut Fourier

Let R ( λ ) be the error term in Weyl’s law for a 3-dimensional Riemannian Heisenberg manifold. We prove that 1 T | R ( t ) | 2 d t = c T 5 2 + O δ ( T 9 4 + δ ) , where c is a specific nonzero constant and δ is an arbitrary small positive number. This is consistent with the conjecture of Petridis and Toth stating that R ( t ) = O δ ( t 3 4 + δ ) .The idea of the proof is to use the Poisson summation formula to write the error term in a form which can be estimated by the method of the stationary phase. The similar result will be also proven in the 2 n + 1 -dimensional case.

Differentiability of excessive functions of one-dimensional diffusions and the principle of smooth fit

Paavo Salminen, Bao Quoc Ta (2015)

Banach Center Publications

The principle of smooth fit is probably the most used tool to find solutions to optimal stopping problems of one-dimensional diffusions. It is important, e.g., in financial mathematical applications to understand in which kind of models and problems smooth fit can fail. In this paper we connect-in case of one-dimensional diffusions-the validity of smooth fit and the differentiability of excessive functions. The basic tool to derive the results is the representation theory of excessive functions;...

Dirichlet forms on symmetric spaces

Christian Berg (1973)

Annales de l'institut Fourier

Let G be a locally compact group and K a compact subgroup such that the algebra L 1 ( G ) of biinvariant integrable functions is commutative. We characterize the G -invariant Dirichlet forms on the homogeneous space G / K using harmonic analysis of L 1 ( G ) . This extends results from Ch. Berg, Séminaire Brelot-Choquet-Deny, Paris, 13e année 1969/70 and J. Deny, Potential theory (C.I.M.E., I ciclo, Stresa), Ed. Cremonese, Rome, 1970. Every non-zero G -invariant Dirichlet form on a symmetric space G / K of non compact type...

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