p. 229 - 242 Universal bounds for positive solutions of doubly degenerate parabolic equations with a source A. F. Tedeev Received: August 28, 2010; Accepted: March 21, 2011 Abstract. We consider a doubly degenerate parabolic equation with a source term of the form For a positive solution of the equation we prove universal bounds and provide blow-up rate estimates under suitable assumptions on p 0(λ, β, N). In particular, we extend some of the recent results by K. Ammar and Ph. Souplet concerning the blow-up estimates for porous media equations with a source. Our proofs are based on a generalized version of the Bochner-Weitzenbök formula and local energy estimates. Keywords: Degenerate parabolic equations; blow-up; universal bounds. AMS Subject classification: Primary: 35K55, 35K65, 35B33 PDF Compressed Postscript Version to read ISSN 0862-9544 (Printed edition) Faculty of Mathematics, Physics and Informatics Comenius University 842 48 Bratislava, Slovak Republic Telephone: + 421-2-60295111 Fax: + 421-2-65425882 e-Mail: amuc@fmph.uniba.sk Internet: www.iam.fmph.uniba.sk/amuc © 2011, ACTA MATHEMATICA UNIVERSITATIS COMENIANAE |