In the present paper, we establish the uniqueness of tangent maps for general weakly holomorphic and locally approximable maps from an arbitrary almost complex manifold into projective algebraic varieties. As a byproduct of the approach and the techniques developed we also obtain the unique tangent cone property for a special class of non-rectifiable positive pseudo-holomorphic cycles. This approach gives also a new proof of the main result by C.Bellettini in [3] on the uniqueness of tangent cones for positive integral (p, p)-cycles in arbitrary almost complex manifolds.
R. CANIATO AND T. RIVIÈRE(2) for any k ∈ N, the space W 1,2 M, R k is the real vector space of functions u = (u 1 , ..., u k ) such that u j ∈ W 1,2 (M ), for every j = 1, ..., k;(3) given a closed smooth manifold N and a smooth isometric embedding N ֒→ R k , for some k ∈ N large enough, we letDefinition 1.1. Let M be any even-dimensional closed smooth manifold and let J be a Lipschitz complex structure on M . Let (N, J N ) be any closed smooth almost complex manifold. We say that a map u ∈ W 1,2 (M, N ) is weakly (J, J N )-holomorphic ifIn Lemma 3.1, we will show that any weakly (J, J N )-holomorphic map taking values into a closed smooth almost Kähler manifold N is weakly harmonic, i.e.where π N : W → N is the nearest-point projection into N , defined on a suitable tubular neighbourhood W of N , and Φ : N ֒→ R k denotes a smooth, isometric embedding of N into R k . Nevertheless, it is well-known that no regularity is ensured for weakly harmonic maps when the dimension of the domain is larger than 2 (see [20]). Thus, we will need to prescribe some additional condition in order to get that the map u is at least stationary harmonic, i.e.We will show (see Lemma 3.3) that imposing the following local, strong approximability property with respect to the W 1,2 -norm sufficies to our purposes.Definition 1.2. Let M, N be closed smooth manifolds. We say that a map u ∈ W 1,2 (M, N ) is locally (strongly) approximable with respect to the W 1,2 -norm if for every open set U ⊂ M such that U is diffeomorphic to some euclidean ball there exists a sequence of smooth maps {u j } j∈N ⊂ C ∞ (M, N ) such that u j → u as j → +∞, strongly in W 1,2 (U, N ).As explained in [6], a map u is locally approximable if and only ifwhere ω ∈ Ω 2 (N ) is any smooth and closed 2-form generating H 2 dR (N ).