Alexei V. Nesteruk

Inflationary Cosmology and Thermodynamics

We present a simple and thermodynamically consistent cosmology with a phenomenological model of quantum creation of radiation due to vacuum decay. Thermodynamics and Einsteins equations lead to an equation in which H is determined by the particle number N. The model is completed by specifying the particle creation rate , which leads to a second-order evolution equation for H. We propose a simple that is naturally defined and that conforms to the thermodynamical conditions: (i) the entropy production rate starts at a maximum; (ii) the initial vacuum (for radiation) is a non-singular regular vacuum and (iii) the creation rate is initially higher than the expansion rate H, but then falls below H. The evolution equation for H then has a remarkably simple exact solution, in which a non-adiabatic inflationary era exits smoothly to the radiation era, without a reheating transition. For this solution, we give exact expressions for the cosmic scale factor, energy density of radiation and vacuum, temperature, entropy and super-horizon scalar perturbations.

Time-like flows of energy momentum and particle trajectories for the Klein-Gordon equation

The Klein-Gordon equation is interpreted in the de Broglie-Bohm manner as a single-particle relativistic quantum mechanical equation that defines unique time-like particle trajectories. The particle trajectories are determined by the conserved flow of the intrinsic energy density, which can be derived from the specification of the Klein-Gordon energy-momentum tensor in an Einstein-Riemann space. The approach is illustrated by application to the simple single-particle phenomena associated with square potentials.

Graviton production as a measure of gravitational entropy in an isotropic universe

The number of gravitons produced within the particle horizon of an isotropic universe describes the capacity of the gravitational field to create matter and is associated with the gravitational entropy. A geometrical expression for gravitational entropy in an isotropic universe is justified in this approach.

Inflationary cosmology with two-component fluid and thermodynamics

We present a simple and self-consistent cosmology with a phenomenological model of quantum creation of radiation and matter due to the decay of the cosmological constant Λ. The decay drives a non-isentropic inflationary epoch, which exits smoothly to the radiation-dominated era, without reheating, and then evolves to the dust era. The initial vacuum for radiation and matter is a regular Minkowski vacuum. The created radiation and matter obeys standard thermodynamic laws, and the total entropy produced is consistent with the accepted value. This paper is an extension of the model with the decaying cosmological constant considered in [1]. We compare our model with the quantum field theory approach to creation of particles in curved space.

Inflationary Cosmology with Scalar Field and Radiation

We present a simple, exact and self-consistentcosmology with a phenomenological model of quantumcreation of radiation due to decay of the scalar field.The decay drives a non-isentropic inflationary epoch, which exits smoothly to the radiation era,without reheating. The initial vacuum for radiation isa regular Minkowski vacuum. The created radiation obeysstandard thermodynamic laws, and the total entropyproduced is consistent with the accepted value.We analyze the difference between the present model andthe model with the decaying cosmological constantconsidered in [1].

The Weyl curvature hypothesis and a choice of the initial vacuum for quantum fields at the cosmological singularity

The meaning of the Weyl curvature hypothesis as a condition to prevent vacuum instability and infinite particle creation at the cosmological singularity is discussed. The restriction on the isotropic expansion law is obtained from the same reasoning which leads to the hypothesis that the Ricci scalar curvature must tend to zero when the singularity is approached.

The motive of the incarnation in Christian theology: consequences for modern cosmology, extraterrestrial intelligence and a hypothesis of multiple incarnations

ABSTRACT This paper addresses the question of the possibility of multiple species-specific incarnations of God in the societies of extraterrestrial beings (if they exist) on exoplanets, proposed for the debate in a recent volume on Astrlotheology. It gives a scientific, philosophical and theological assessment of some of its claims and concludes by formulating the position of the author on multiple incarnations in the context of modern cosmology and Orthodox theology.

Philosophical Foundations of the Dialogue between Science and Theology

The paper discusses the philosophical difficulties in conducting the dialogue between science and theology. It is argued that theology deals with the event-like phenomena which cannot be presented in phenomenality of objects (what happens in science). Correspondingly, in order to incorporate the givens of theology (the “data” of religious experience) into a philosophical framework one needs to extend philosophy beyond its metaphysical and transcendental setting. This extension inevitably leads to the recognition of the fact that the foundation of both science and theology originates in human beings, having an ambiguous position in the universe which cannot be explicated on metaphysical grounds. The phenomenon of man remains inexplicable to man himself thus creating an ultimate reference point of the contingent facticity of both science and theology. The so called dialogue between science and theology demonstrates that the difference in hermeneutics of representation of the world in the phenomenality of objects and the inaugural events of human life and religious experience pertains to the basic characteristic of the human condition and that the intended overcoming of this difference under the disguise of the “dialogue” represents, in fact, an existentially untenable enterprise. Discussions on the differences in experience of the world and experience of God are profoundly timely for further articulation of the sense of the human condition, but not for its change.

From a Neo-Patristic Legacy of Georges Florovsky to the Radical Theological Commitment in the Dialogue with Science

The article discusses the possible ways of the dialogue between science and theology in the context of modern atheism and secularism. It is argued that the dialogue cannot be symmetric and that the task of a theological critique of secularism is extended to the critical analysis of modern scientific theories in the context of existential problems of humankind, as well as of any particular person. As a matter of a historical precedent one discusses an idea of a neopatristic synthesis in theology advanced by a famous Russian philosopher and theologian Fr. George Florovsky. The paper discusses a possibility of extending of a neopatristic ethos towards the dialogue between theology and science. One then accentuates the main problems of the dialogue such as the centrality of human person and primacy of existential faith as being the basis for a scientific creativity. Any tension between theology and science is destined to disappear if they both are seen as flourishing from the same human experience of existence-communion. Science thus cannot be detached from theology and it is in a complex with theology that it can be properly understood and treated.

Universe, Incarnation and Humanity: Theology of Thomas Torrance and Modern Cosmology

In this paper we give a philosophical analysis of the spatial paradox of incarnation in theology of the famous XXth century Scottish theologian Thomas Torrance. The paradox is interpreted in the context of modern cosmology, in particular in relation to a basic cosmological principle of uniformity of space in the universe. As a step beyond Torrance’s theology the paper analyses the paradox of the incarnation for the elucidation of the sense of the human condition and, in particular, the concept of person as the center of disclosure and manifestation of the universe.