We show that the singularities in the dynamical bosonic response functions of a generic 2D Fermi liquid give rise to universal, non-analytic corrections to the Fermi-liquid theory. These corrections yield a T 2 term in the specific heat, T terms in the effective mass and the uniform spin susceptibility χs(Q = 0, T ), and |Q| term in χs(Q, T = 0). The existence of these terms has been the subject of recent controversy, which is resolved in this paper. We present exact expressions for all non-analytic terms to second order in a generic interaction U (q) and show that only U (0) and U (2pF ) matter.PACS numbers: 71.10Ay, 71.10PmThe universal features of a Fermi liquid and their physical consequences continue to attract the attention of the condensed-matter community. In a generic Fermi liquid, the imaginary part of the retarded fermionic selfenergy Σ R (k, ω) on the mass shell is determined solely by fermions in a narrow (∼ ω) energy range around the Fermi surface and behaves as Σ ′′ ∝ ω 2 + (πT ) 2 [1]. This regular behavior of the self-energy has a profound effect on such observables as the specific heat and uniform spinand charge susceptibilities, which have the same functional dependences as for free fermions, i.e., the specific heat is linear in T and the susceptibilities approach finite values at T = 0. A regular behavior of the fermionic self-energy is also in line with a general reasoning that turning on the interaction in D > 1 should not affect drastically the low-energy properties of a system [2], unless special circumstances, e.g., a proximity to a quantum phase transition [3], interfere.The subject of this paper is the analysis of non-analytic corrections to the Fermi-liquid behavior in a generic, clean Fermi liquid. These corrections are universal in a sense that they are determined by fermions near the Fermi surface. It has been known for some time that corrections to the Fermi-liquid form of Σ ′′ (ω) do not form a regular, analytic series in ω 2 but rather scale as ω D for 2 ≤ D ≤ 3, with an extra logarithm in D = 2 [1,4,5]. [For 1 < D < 2 this form persists, but it is not a "correction" anymore.] These non-analytic ω D terms (as well as non-analytic vertex corrections) are of fundamental interest as they may give rise to anomalous temperature and momentum dependences of observable quantities. A well-known example is the T 3 ln T term in the specific heat of a 3D Fermi liquid, caused by the anomalous term Σ ′′ (ω) ∝ ω 3 (and hence Σ ′ (ω) ∝ ω 3 log ω) [4]. A related example is the linear-in-T correction to the conductivity of a weakly disordered 2D system [6,7,8]. Non-analytic corrections are also important for the theory of quantum critical phenomena in itinerant ferromagnets [9], as a non-analyticity of the static spin susceptibility changes the nature of the phase transition [10].Belitz, Kirkpatrick and Vojta (BKV) [12] and, later, Misawa [11] argued that the non-analyticity in the fermionic self-energy should gives rise to a non-analytic momentum expansion of the particle-hole susceptibility χ(Q...