We consider deterministic fast–slow dynamical systems on $$\mathbb {R}^m\times Y$$
R
m
×
Y
of the form $$\begin{aligned} {\left\{ \begin{array}{ll} x_{k+1}^{(n)} = x_k^{(n)} + n^{-1} a\big (x_k^{(n)}\big ) + n^{-1/\alpha } b\big (x_k^{(n)}\big ) v(y_k), \\ y_{k+1} = f(y_k), \end{array}\right. } \end{aligned}$$
x
k
+
1
(
n
)
=
x
k
(
n
)
+
n
-
1
a
(
x
k
(
n
)
)
+
n
-
1
/
α
b
(
x
k
(
n
)
)
v
(
y
k
)
,
y
k
+
1
=
f
(
y
k
)
,
where $$\alpha \in (1,2)$$
α
∈
(
1
,
2
)
. Under certain assumptions we prove convergence of the m-dimensional process $$X_n(t)= x_{\lfloor nt \rfloor }^{(n)}$$
X
n
(
t
)
=
x
⌊
n
t
⌋
(
n
)
to the solution of the stochastic differential equation $$\begin{aligned} \mathrm {d} X = a(X)\mathrm {d} t + b(X) \diamond \mathrm {d} L_\alpha , \end{aligned}$$
d
X
=
a
(
X
)
d
t
+
b
(
X
)
⋄
d
L
α
,
where $$L_\alpha $$
L
α
is an $$\alpha $$
α
-stable Lévy process and $$\diamond $$
⋄
indicates that the stochastic integral is in the Marcus sense. In addition, we show that our assumptions are satisfied for intermittent maps f of Pomeau–Manneville type.