Li, TJ (reprint author), Chinese Acad Sci, Inst Theoret Phys, State Key Lab Theoret Phys, Beijing 100190, Peoples R China.
[Li, Tianjun] Chinese Acad Sci, Inst Theoret Phys, State Key Lab Theoret Phys, Beijing 100190, Peoples R China
; [Li, Tianjun] Chinese Acad Sci, Inst Theoret Phys, Kavli Inst Theoret Phys China KITPC, Beijing 100190, Peoples R China
; [Li, Tianjun] Univ Elect Sci & Technol China, Sch Phys Elect, Chengdu 610054, Peoples R China
; [Li, Zhijin
; Nanopoulos, Dimitri V.] Texas A&M Univ, George P & Cynthia W Mitchell Inst Fundamental Ph, College Stn, TX 77843 USA
; [Nanopoulos, Dimitri V.] Houston Adv Res Ctr, Astroparticle Phys Grp, The Woodlands, TX 77381 USA
; [Nanopoulos, Dimitri V.] Acad Athens, Div Nat Sci, Athens 10679, Greece
We propose a natural inflation model driven by an imaginary or axionic component of a Kahler modulus in string-inspired supergravity. The shift symmetry of the axion is gauged under an anomalous U(1)(X) symmetry, which leads to a modulus-dependent Fayet-Iliopoulos (FI) term. The matter fields are stabilized by F-terms, and the real component of the modulus is stabilized by the U(1)(X) D-term, while its axion remains light. Therefore, the masses of real and imaginary components of the modulus are separated at different scales. The scalar potential for natural inflation is realized by the superpotential from the non-perturbative effects. The trans-Planckian axion decay constant, which is needed to tit with BICEP2 observations, can be obtained naturally in this model.