This award provides funding to support the participation of early-career researchers, including graduate students, postdoctoral fellows, and recently appointed tenure-track assistant professors from U.S. institutions, in the six-month program on Geometric Spectral Theory and Applications, hosted and funded by the Isaac Newton Institute for Mathematical Sciences (INI), Cambridge, UK, from January to June 2026. The NSF funds will be used exclusively to support U.S.-based researchers attending one of the week-long workshops within the program. A significant portion of the funds is designated for early-career researchers (ECRs) participating in the Emerging Horizons in Geometric Spectral Theory: An ECRs Workshop, to be held February 2-6, 2026. Applications to attend other workshops, Geometry of Eigenvalues (March 23-27, 2026), Interactions of Geometric Spectral Theory with Numerical Methods and Applications (April 13-17, 2026), and Random and Arithmetic Models in Spectral Theory (May 11-15, 2026) will also be considered. Distributing funding across all workshops maximizes collaborative opportunities and offers greater flexibility, thereby enhancing participation by U.S. researchers. Participation in these activities is open to all who meet the scientific criteria. Applications will be submitted through the INI program website, where U.S.-based applicants will be offered the option to apply for NSF funding. The Principal Investigators of this grant will oversee the evaluation of N