http://www.mdpi.com/journal/entropy/special_issues/entropy-feature-papers/ Submission All papers should be submitted to entropy@mdpi.com with copy to the guest editor. To be published continuously until the deadline and papers will be listed together at the special websites. Both, research articles and review articles are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editors for announcment on this website. Submitted papers should not have been published previously, nor be under consideration for publication elsewhere. All papers are refereed through a peer-review process. A guide for authors, sample copies and other relevant information for submitting papers are available on the Instructions for Authors page. Entropy is an international peer-reviewed quarterly journal published by MDPI. Please visit the Instructions for Authors page before submitting a paper. Open Access publication fees are 800 CHF per paper. English correction fees (250 CHF) will be added in certain cases (1050 CHF per paper for those papers that require extensive additional formatting and/or English corrections.). http://www.mdpi.com/1099-4300/12/4/932/ It is demonstrated that entropy and its density play a significant role in solving the problem of the vacuum energy density (cosmological constant) of the Universe and hence the dark energy problem. Taking this in mind, two most popular models for dark energy—Holographic Dark Energy Model and Agegraphic Dark Energy Model—are analysed. It is shown that the fundamental quantities in the first of these models may be expressed in terms of a new small dimensionless parameter that is naturally occurring in High Energy Gravitational Thermodynamics and Gravitational Holography (UV-limit). On this basis, the possibility of a new approach to the problem of Quantum Gravity is discussed. Besides, the results obtained on the uncertainty relation of the pair “cosmological constant–volume of space-time”, where the cosmological constant is a dynamic quantity, are reconsidered and generalized up to the Generalized Uncertainty Relation. http://www.mdpi.com/1099-4300/12/4/932/ Wed, 14 Apr 2010 00:00:00 CEST Entropy 2010-04-14 12 4 Article 932 952 1099-4300 Entropy in the Present and Early Universe: New Small Parameters and Dark Energy Problem 2010-04-14 doi: 10.3390/e12040932 Shalyt-Margolin