# Mathematical Physics

## 1905 Submissions

[3] **viXra:1905.0268 [pdf]**
*submitted on 2019-05-17 17:43:20*

### Ecriture Détaillée Des Equations de la Relativité Générale :Cas D’Une Métrique Diagonale

**Authors:** Abdelmajid Ben Hadj Salem

**Comments:** 22 Pages. In French.

In this note, we study Einstein equations (EE) of general relativity considering a manifold M with a diagonal metric g_{ij}. We calculate the expression of the components of Ricci and Riemann tensors and the value of the scalar curvature R. Then we give the expression of the (EE) :
-a- for the case where g_{ii}=g_i=g_i(x_i);
-b- for the case where g_1=g_1(x_1=t) and g_i=g_i(t,x_i) for i=2,3,4$;
-c- for the case (b) with x_4=z_0=constant.

**Category:** Mathematical Physics

[2] **viXra:1905.0142 [pdf]**
*submitted on 2019-05-09 19:53:08*

### (LFs and Gravity Working Paper Variant 1.0 7 Pages 13.04.2019) Life Forms, "Hybrid" Causality, Gravity and Hierarchical Parallel Universes

**Authors:** Andrei Lucian Dragoi

**Comments:** 7 Pages.

This paper proposes a new definition of life forms in relation to a new type of “hybrid” causality, gravity and the possible existence of hierarchical parallel universes.
Keywords: life forms, gravity, hierarchical parallel universes;

**Category:** Mathematical Physics

[1] **viXra:1905.0012 [pdf]**
*submitted on 2019-05-01 14:07:09*

### A Mathematical Overview of Mass and Energy Conservation in Modern Physics

**Authors:** Dang Dang

**Comments:** 28 Pages.

The idea of energy, matter, and motion has perplexed many philosophers and
physicists from antiquity to modern physics, from Plato to Einstein. New and
developing physical theories raise different interpretations of energy and matter but
no complete theory of everything exists at present. However, there is a law we can
almost take for granted: the law of conservation of energy, which states that
energy cannot be created nor destroyed although it can be transformed from one
form to another. After establishing the foundational theory and history of
conservation of energy, this literature review aims to provide an overview of the
concept of mass and energy conservation in two of the most fundamental physical
theories - quantum mechanics and general relativity. Consequences and challenges
of mass-energy conservation and equivalence - dark energy - is studied in an
introductory manner

**Category:** Mathematical Physics