The Cosmic microwave background (CMB) anisotropies predicted by two
cosmological models are compared, one of them is the standard model of general
relativity with cold dark matter and cosmological constant, whereas the second
model is based on a consistent vector-tensor theory of gravitation explaining
solar system and cosmological observations. It is proved that the resulting
differences — between the anisotropies of both models — are due to the
so-called late integrated Sachs Wolfe effect and, consequently, cross
correlations between maps of CMB temperatures and tracers of the dark matter
distribution could be used in future to select one of the above models. The
role of reionization is analysed in detail.
Examining the Conclusions of the Text
The article compares the predictions of two cosmological models: the standard model of general relativity with cold dark matter and a cosmological constant, and a model based on a vector-tensor theory of gravitation. The comparison focuses on the anisotropies of the Cosmic Microwave Background (CMB).
It is demonstrated that the differences in anisotropies between the two models arise from the late integrated Sachs-Wolfe effect. This effect can be understood as the interaction between CMB photons and the changing gravitational potential of the matter distribution in the universe. By analyzing cross-correlations between maps of CMB temperatures and tracers of dark matter distribution, it may be possible to distinguish between the two cosmological models.
The role of reionization, the process through which neutral hydrogen in the early universe becomes ionized, is also examined in detail. Reionization has a significant impact on the CMB anisotropies and is an important factor to consider when studying cosmological models.
Future Roadmap: Challenges and Opportunities
Roadmap for Readers:
- Understanding the standard model of general relativity with cold dark matter and a cosmological constant as one of the compared cosmological models.
- Exploring the vector-tensor theory of gravitation as an alternative model and its explanations for solar system and cosmological observations.
- Learning about the late integrated Sachs-Wolfe effect and its role in creating differences in CMB anisotropies between the two models.
- Investigating how cross-correlations between CMB temperature maps and tracers of dark matter distribution can be utilized to select one of the models.
- Examining the importance of reionization and its impact on CMB anisotropies in relation to the cosmological models.
Potential Challenges:
- Understanding the complexities of general relativity and the vector-tensor theory of gravitation.
- Grasping the mathematical concepts related to the late integrated Sachs-Wolfe effect and cross-correlations analysis.
- Keeping up with advancements and updates in observational techniques for mapping CMB temperatures.
- Staying informed about current research on reionization and its effects on the CMB anisotropies.
Potential Opportunities:
- Contributing to the selection of a more accurate cosmological model through analysis of cross-correlations between CMB temperature maps and dark matter tracers.
- Exploring the potential implications of verifying one model over the other for our understanding of the universe’s composition and expansion.
- Participating in ongoing research and discussions surrounding reionization and its impact on the CMB.
- Engaging with the scientific community and academic institutions to stay updated on advancements in cosmology and gravitational theories.
Conclusion:
By studying the differences in CMB anisotropies between the standard model of general relativity with cold dark matter and a cosmological constant, and a vector-tensor theory of gravitation, researchers aim to make progress in selecting the most accurate cosmological model. The late integrated Sachs-Wolfe effect and cross-correlations analysis between CMB temperature maps and dark matter tracers play crucial roles in this endeavor. Additionally, understanding the impact of reionization on the CMB will contribute to further advancements in our understanding of the universe. While challenges exist in comprehending complex theories and keeping up with cutting-edge research, opportunities for contributing to cosmological knowledge and engaging with the scientific community abound.