A discovery of cosmic birefringence could lead the method to revealing the nature of dark matter and dark energy, and so future missions are focused on making more accurate observations of the CMB.Incorporating Gravitational Lensing into Theoretical CalculationsTo do this, it is important to improve the accuracy of current theoretical computations, but these computations so far have not been sufficiently accurate due to the fact that they do not take gravitational lensing into account. A new study by a set of researchers, led by The University of Tokyo Department of Physics and Research Center for Early Universe doctoral student Fumihiro Naokawa, and Center for Data-Driven Discovery and Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) Project Assistant Professor Toshiya Namikawa, developed a theoretical estimation of cosmic birefringence that integrates gravitational lensing effects, and worked on the development of a mathematical code for cosmic birefringence that includes gravitational lensing effects, which will be important for future analyses.Simons Observatory in Chile. As an outcome, the scientists found that if gravitational lensing is disregarded, the observed cosmic birefringence signal can not be fitted well by the theoretical prediction, which would statistically decline the real theory.In addition, the pair developed simulated observational data that will be obtained in future observations to see the effect of gravitational lensing in the search for ALPs.
By Kavli Institute for the Physics and Mathematics of the Universe January 14, 2024Cosmic Microwave Background (CMB) polarized light subjected to gravitational lensing effects, in addition to cosmic birefringence. The blue dots show the signals when the gravitational lensing effect is disregarded, and the red dots are the signals when the gravitational lensing result is considered. A discovery of cosmic birefringence could lead the way to exposing the nature of dark matter and dark energy, and so future objectives are focused on making more precise observations of the CMB.Incorporating Gravitational Lensing into Theoretical CalculationsTo do this, it is important to improve the precision of existing theoretical calculations, however these estimations so far have not been adequately accurate because they do not take gravitational lensing into account. A brand-new research study by a set of scientists, led by The University of Tokyo Department of Physics and Research Center for Early Universe doctoral student Fumihiro Naokawa, and Center for Data-Driven Discovery and Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) Project Assistant Professor Toshiya Namikawa, established a theoretical calculation of cosmic birefringence that incorporates gravitational lensing effects, and worked on the development of a numerical code for cosmic birefringence that consists of gravitational lensing results, which will be indispensable for future analyses.Simons Observatory in Chile. As an outcome, the scientists found that if gravitational lensing is ignored, the observed cosmic birefringence signal can not be fitted well by the theoretical prediction, which would statistically reject the true theory.In addition, the pair produced simulated observational data that will be gotten in future observations to see the result of gravitational lensing in the search for ALPs.
