Entropy in the Present and Early Universe

Entropy

About 160 years ago, the concept of entropy was introduced in thermodynamics by Rudolf Clausius. Since then, it has been continually extended, interpreted, and applied by researchers in many scientific fields, such as general physics, information theory, chaos theory, data mining, and mathematical linguistics. This paper presents The Entropy Universe, which aims to review the many variants of entropies applied to time-series. The purpose is to answer research questions such as: How did each entropy emerge? What is the mathematical definition of each variant of entropy? How are entropies related to each other? What are the most applied scientific fields for each entropy? We describe in-depth the relationship between the most applied entropies in time-series for different scientific fields, establishing bases for researchers to properly choose the variant of entropy most suitable for their data. The number of citations over the past sixteen years of each paper proposing a new entropy ...

Zenodo , 2025

This research proposes a new universal theory fully grounded in entropy dynamics, serving as an alternative to conventional frameworks such as string theory. Unlike traditional approaches, which rely on hypothetical dimensions or particles, this framework is based solely on entropy flows, gradients, and patterns. All observable phenomena-including matter, energy, forces, and spacetime-emerge naturally from the dynamics of entropy.

2011

Thermodynamic entropy is a pathway for transitioning from the mechanical world of fundamental physics theory to the world of probabilities, statistics, microstates, and information theory as applied to analyses of the universe. This paper proposes to explain the physical meaning of thermodynamic entropy, and, its connection to Boltzmann’s entropy. The inclusion of Boltzmann’s constant in his definition of entropy establishes the connection. The physical basis of Boltzmann’s constant and his entropy are explained. These explanations first require new analyses of fundamental properties such as force and mass.

The Physical Meaning of Entropy, 2023

I propose here a new physical interpretation of entropy based on the concept of isotropy that results compatible with both Clausius and Boltzmann interpretations. I also introduce a basic principle of physics that, although implicitly assumed, has never been explicitly declared as such a principle: the Principle of Identicality (all elementary particles of the same type are identical). Both, the new principle and the new interpretation of entropy as isotropy make it possible to deduce in formal terms three laws on the evolution of entropy that are equivalent to the Second and the Third Law of Thermodynamics. All the oddities and mysteries of the enigmatic concept of entropy and of its fundamental laws disappear when examined from this new perspective: Identicality and random evolution formally imply isotropy, and then entropy.

Entropy, 2010

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 analyzed. It is shown that the fundamental quantities in the first of these models may be expressed in terms of a new small dimensionless parameter. It is revealed that this parameter 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 constantvolume of space-time", where the cosmological constant is a dynamic quantity, are reconsidered and generalized up to the Generalized Uncertainty Relation

viXra, 2018

Following worries that the entropy functions of classical thermodynamics and statistical thermodynamics were not equivalent, attention is drawn here to work by Lazar Mayants indicating that this is not the case and the two are, in fact, equivalent.

2009

In the 12th Marcel Grossmann Meeting, July 9 th , 2009, the author raised the issue of whether early graviton production could affect non-Gaussian contributions to DM density profiles. Non gaussianity of evolving cosmological states is akin to asking if there is a way to get quantum contributions due to squeezed initial vacuum states which act highly non classscially. If particle counting algorithms in graviton production is important as for entropy, and if entropy perturbations affects the density profile of dark matter clumping prifiles, then there is room to ask to what degree initial perturbations affecting structure formation are due to classical/ non linear processes, or more quantum theoretic states. If squeezing of the initial vacuum states is essential in the relic conditions, then quantization is unavoidable. If squeezing is not essential, then coherent initial vacuum states may contribute in semi classical ways to GW production. The end result of this stated inquiry may be answering if or not gravity in the onset of inflation is a quantized field. Or if a highly non linear set of complex initial conditions for gravity can be stated using purely classical models, as T"Hooft, Corda, and others believe. Note, also that Bojowald as of 2008 has left the degree of squeezing of initial vacuum states in the region of space as an open problem. In Bojowald"s model of a cosmological bounce, the degree of squeezing is a measure of what strength the "bounce" from an initial configuration of the universe takes, and how strongly quantum effects contribute to the evolution of the LQG cosmos, after inflation commences. Similar questions are being raised as to the necessity of squeezing of initial vacuum states and if or not coherency of initial states is initially largely achievable, before the rapid expansion of the universe commences. Finally, and not least is a series of questions as to what conditions which would either require high or low frequencies as to relic signals from the big bang. As it is, large spatial dimensions which could induce far lower initial frequencies for relic signals are popular in many string theory models. The author views this assumption as of debatable validity, as well as the assumption made by Arkani Hamid that largely does away with coherency of initial vacuum states and specifies highly quantum , low frequency generation of relic GW. 10 9 Review of simple models as to gravitons as produced either by (Quantum gravity) strings , LQG,(or by processes which may not be Quantum Gravity based?) We wish now to review what may be some of the counting algorithms appropriate for entropy generation, and which may contribute to answering if or not GW are mandated to be, from the beginning either a classical versus a quantum processes. IN part this next page is due to concepts A.Beckwith presented in Rencontres De Blois, 2009, and is a starting point for our inquiry as to the necessity, or lack of , of modeling Gravity as either classical / quantum based in relic conditions.

I discuss the statistical mechanics of gravitating systems and in particular its cosmological implications, and argue that many conventional views on this subject in the foundations of statistical mechanics embody significant confusion; I attempt to provide a clearer and more accurate account. In particular, I observe that (i) the role of gravity in entropy calculations must be distinguished from the entropy of gravity, that (ii) although gravitational collapse is entropy-increasing, this is not usually because the collapsing matter itself increases in entropy, and that (iii) the Second Law of Thermodynamics does not owe its validity to the statistical mechanics of gravitational collapse.

If the universe had been born in a high entropy, equilibrium state, there would be no stars, no planets and no life. Thus, the initial low entropy of the universe is the fundamental reason why we are here. However, we have a poor understanding of why the initial entropy was low and of the relationship between gravity and entropy. We are also struggling with how to meaningfully define the maximum entropy of the universe. This is important because the entropy gap between the maximum entropy of the universe and the actual entropy of the universe is a measure of the free energy left in the universe to drive all processes. I review these entropic issues and the entropy budget of the universe. I argue that the low initial entropy of the universe could be the result of the inflationary origin of matter from unclumpable false vacuum energy. The entropy of massive black holes dominates the entropy budget of the universe. The entropy of a black hole is proportional to the square of its mass. Therefore, determining whether the Maximum Entropy Production Principle (MaxEP) applies to the entropy of the universe is equivalent to determining whether the accretion disks around black holes are maximally efficient at dumping mass onto the central black hole. In an attempt to make this question more precise, I review the magnetic angular momentum transport mechanisms of accretion disks that are responsible for increasing the masses of black holes 22.1 The Entropy of the Observable Universe Stars are shining, supernovae are exploding, black holes are forming, winds on planetary surfaces are blowing dust around, and hot things like coffee mugs are cooling down. Thus, the entropy of the universe S uni , is increasing, and has been

Thermodynamics is a physical branch of science that governs the thermal behavior of dynamical systems from those as simple as refrigerators to those as complex as our expanding universe. The laws of thermodynamics involving conservation of energy and nonconservation of entropy are, without a doubt, two of the most useful and general laws in all sciences. The first law of thermodynamics, according to which energy cannot be created or destroyed, merely transformed from one form to another, and the second law of thermodynamics, according to which the usable energy in an adiabatically isolated dynamical system is always diminishing in spite of the fact that energy is conserved, have had an impact far beyond science and engineering. In this paper, we trace the history of thermodynamics from its classical to its postmodern forms, and present a tutorial and didactic exposition of thermodynamics as it pertains to some of the deepest secrets of the universe.