##### News Letter on Gravitational Field Research: April -2019

**A novel photothermal excitation cracked medium in gravitational field with two-temperature and hydrostatic initial stress**

A New Approach model for a theory of 2 temperature with finite linear gap Mode-I crack within a semi-infinite semiconductive medium is bestowed. The mechanical force influence throughout the photothermal method with the influence of gravity and hydrostatic initial stress in 2 dimensions are used. The transient compressive stress wave travels on the crack from the loading region to the crack face. mistreatment mathematical strategies underneath the compass of various 3 theories (Lord–Şhulman (LS) includes one time constant, Green–Lindsay (GL) includes 2 relaxation times, and therefore the classical ever-changing coupled theory (CD)). the precise expression of the physical quantities and therefore the 2 temperature constant ratios are obtained analytically mistreatment the harmonic wave technique and illustrated diagrammatically. Comparisons between the results of the 3 theories also are introduced. **[1]**

**MHD waves in plasma in gravitational field**

We study waves in plasma by victimization magnetohydrodynamic equations (MHD). Dispersion equation and reflection co-efficient for MHD waves are derived victimization this magnetohydrodynamic model for equal, gravitationaly stratified plasma during a horizontal nonuniform magnetic flux. Alfven and sound speeds are constant. during this model analytical solutions will be obtained for linearized perturbations. They gift 3 wave modes: the Alfven mode, the quick and also the slow magnetoacoustic mode. These modes are changed by gravity. In nonmagnetized case dispersion equation describes gravito-acoustic waves. **[2]**

**Three-Dimensional Printing in a Non-Gravitational Field**

We study waves in plasma by victimization magnetohydrodynamic equations (MHD). Dispersion equation and reflection co-efficient for MHD waves are derived victimization this magnetohydrodynamic model for equal, gravitationaly stratified plasma throughout a horizontal heterogeneous magnetic flux. Alfven and sound speeds are constant. throughout this model analytical solutions are going to be obtained for linearized perturbations. They gift three wave modes: the Alfven mode, the fast and additionally the slow magnetoacoustic mode. These modes are modified by gravity. In nonmagnetized case dispersion equation describes gravito-acoustic waves.** [3]**

**Using Jupiter’s gravitational field to probe the Jovian convective dynamo**

Convective motion within the deep metallic element region of Jupiter is believed to get its field of force, the strongest within the system. The amplitude, structure and depth of the convective motion are unknown. A promising method of inquiring the Jovian convective generator is to live its result on the external field, a task to be shortly undertaken by the Roman deity craft. we have a tendency to calculate the attraction signature of non-axisymmetric convective motion within the Jovian metallic element region and show that with sufficiently correct measurements it will reveal the character of the deep convection.** [4]**

**Modification of Einstein’s Gravitational Field Equation and Cracking of Foundational Difficulties in Physics**

In the framework of theory of gravitation of general theory of relativity, this text has consistently and radically resolved the matter of galaxy formation and a few important cosmological puzzles. A flaw with Einstein’s equation of field is first off corrected and therefore the foundations of general theory of relativity are formed and developed, and reference frame is tested to be infinite, growth and contraction of universe are tested to be in a circle, the singular purpose of massive bang is of course eliminated, celestial bodies and galaxies are tested growing up with cosmic growth, as an example Earth’s mass and radius at this time increase by one.2 trillion tons and zero.45mm, severally during a year, in response to that fixed satellites rise by two.7mm.** [5]**

**Reference**

**[1] **Lotfy, K., Gabr, M. and Hassan, W., 2019. A novel photothermal excitation cracked medium in gravitational field with two-temperature and hydrostatic initial stress. *Waves in Random and Complex Media*, *29*(2), pp.344-367. (Web Link)

**[2]** Jovanovic, G., 2019, February. MHD waves in plasma in gravitational field. In *AIP Conference Proceedings* (Vol. 2075, No. 1, p. 090008). AIP Publishing. (Web Link)

**[3] **Kendurkar, C., Deshmukh, K., Bahegavankar, M., Shukla, J. and Marachakkanavar, M., 2019. Three-Dimensional Printing in a Non-Gravitational Field. *Available at SSRN 3356752*. (Web Link)

**[4] **Using Jupiter’s gravitational field to probe the Jovian convective dynamo

Dali Kong, Keke Zhang & Gerald Schubert

Scientific Reports **volume ****6**, Article number: 23497 (2016) (Web Link)

**[5] **Modification of Einstein’s Gravitational Field Equation and Cracking of Foundational Difficulties in Physics

**Jian Liang Yang
**Department of Mathematics, Zhoukou University 266744, China. (Web Link)