The phrase "a subject of extensive research" is correct and usable in written English.
You can use it when discussing a topic that has been thoroughly studied or investigated in a particular field.
Example: "Climate change has become a subject of extensive research in recent years, with scientists exploring its impacts on ecosystems and human health."
Alternatives: "a topic of significant study" or "an area of in-depth investigation."
Drying is a subject of extensive research in the last three decades due to its importance in manufacturing many types of products.
This monograph delves specifically into the topic of the geometric properties of Banach spaces and nonlinear iterations, a subject of extensive research over the past thirty years.
More recently, work on this problem has been an integral part of the development of modern mathematical logic, and it has become a subject of extensive research in its own right.
A map T : X → X on a metric space ( X, d ) is called a weak ϕ-contraction if there exists a strictly increasing function ϕ : [ 0, ∞ ) → [ 0, ∞ ) with ϕ ( 0 ) = 0 such that d ( T x, T y ) ≤ d ( x, y ) − ϕ ( d ( x, y ) ), for all x, y ∈ X. We notice that these types of contractions have also been a subject of extensive research (see, e.g., [44 49]).
This model circuit has been a subject of extensive research during the last decade.
As a result, targeting VEGFA has been a subject of extensive research during the last decades.
The ubiquitin proteasome system (UPS) has long been a subject of extensive biomedical research because of its importance to proper cellular function.
The goal to control the dynamics of high-rise buildings either to ameliorate the damage or prevent their destruction when subject to an earthquake excitation has been subject of extensive research.
However, this area has been the subject of extensive research over more than a decade.
As a noninvasive neurostimulation technique, TENS has gradually been the subject of extensive research in the treatment of headache disorders.
As a result, coexistence issues on unlicensed bands have been the subject of extensive research, and in particular, it has been shown that IEEE 802.11 networks can significantly degrade the performance of Zigbee/802.15.4 networks when operating on overlapping frequency bands [1].
