TY - BOOK AU - Ershov,Mikhail AU - Jaikin-Zapirain,Andrei AU - Kassabov,Martin TI - Property (T) for groups graded by root systems T2 - Memoirs of the American Mathematical Society SN - 9781470426040 (alk. paper) U1 - 510 23 PY - 2017/// CY - Providence : PB - American Mathematical Society, KW - Root systems (Algebra) N1 - Includes bibliographical references and index; Chapter 1. Introduction -- Chapter 2. Preliminaries -- Chapter 3. Generalized spectral criterion -- Chapter 4. Root Systems -- Chapter 5. Property $(T)$ for groups graded by root systems -- Chapter 6. Reductions of root systems -- Chapter 7. Steinberg groups over commutative rings -- Chapter 8. Twisted Steinberg groups -- Chapter 9. Application: Mother group with property $(T)$ -- Chapter 10. Estimating relative Kazhdan constants -- Appendix A. Relative property $(T)$ for $(\mathrm St_n(R)\ltimes R^n,R^n)$ N2 - Introduces and studies the class of groups graded by root systems. The authors prove that if $\Phi$ is an irreducible classical root system of rank $\geq 2$ and $G$ is a group graded by $\Phi$, then under certain natural conditions on the grading, the union of the root subgroups is a Kazhdan subset of $G$. ER -