Study of the tensor power spectrum for the Starobinsky inflationary model using the uniform approximation method

The origin of the universe has been a big question along human existence. The Big Bang model was the first scientific step in order to answer this question. Then, Inflationary Cosmology comes to solve the fine-tuning problems emerging from the classical theory of the BB. Inflation is understood as an exponential expansion that occurred in the early universe, and despite its great help in order to understand its behavior there is still no model that explains it satisfactorily. The way to realize the validity of the model is comparing the calculated values with the experimentally observed values. Then, this work will make use of the Starobinsky model which is the most accepted model for the results it yields, in order to calculate the power spectrum of tensor perturbations by three different methods, numerical integration, slow-roll approximation and uniform approximation, making more emphasis in the third one. By consequence, we can also calculate the tensor spectral index nT and the tensor-to-scalar ratio r. We will show that the slow-roll method gives a better result when we evaluate the power spectrum. But, when we calculate r the accuracy of the uniform approximation compares favorably with the numerical results.

• Үндсэн зохиолч: Altamirano Coello, David Alejandro (author)
• Формат: bachelorThesis
• Хэл сонгох: eng
• Хэвлэсэн: 2021
• Нөхцлүүд: Cosmología inflacionaria; Perturbaciones cosmológicas; Modelo de Starobinsky; Espectro de potencia; Integración numérica; Aproximación Slow-Roll; Método de aproximación uniforme; Inflationary cosmology; Cosmological perturbations; Starobinsky Model; Power spectrum; Numerical integration; Slow-Roll approximation; Uniform approximation method
• Онлайн хандалт: http://repositorio.yachaytech.edu.ec/handle/123456789/391