A slight variant $\tilde Mot\_{num}(k,\mathbb{Q})$ of the category of pure motives $Mot\_{num}(k,\mathbb{Q})$ is a Tannakian category equivalent to a category of representations of some algebraic group $GMot\_k$ (the Motivic galois group):


$$
Mot\_{num}(k,\mathbb{Q}) \simeq Rep(GMot\_k)
\,.
$$


[nLab](https://ncatlab.org/nlab/show/motivic+Galois+group)



> 
> What it is known about the Derived category version (The derived category of motives) of this equivalence?
> 
> 
> 


**Equivalence between the sub-category of compact objects of (say for example) étale Motivic sheaves and the derived category of representations of finite dimension of (Ayoub) Motivic galois groups**



Derived version of equivalence between motives and representations of Motivic galois groups?
Let $k$ be a field and $\operatorname{DM}\_{gm}(k)\_{\mathbb Q}$ the ∞-category of rational geometric motives over $k$. A mixed Weil cohomology theory induces a symmetric monoidal exact functor


$$
R: \operatorname{DM}\_{gm}(k)\_{\mathbb Q} \to D\_c(\mathbb Q),
$$


where $D\_c(\mathbb Q)$ are the compact=dualizable objects in the derived ∞-category of $\mathbb Q$.
For abstract reasons, there exists a best possible commutative Hopf algebra $H$ in $D(\mathbb Q)$ such that, if $G=\operatorname{Spec}(H)$, then $R$ lifts to


$$
\tilde R: \operatorname{DM}\_{gm}(k)\_{\mathbb Q} \to \operatorname{Rep}\_{D\_c(\mathbb Q)}(G).
$$


This general construction can be found in [this paper](https://arxiv.org/pdf/1112.1761v3.pdf) by Iwanari.
As you know, Ayoub has also [constructed](http://user.math.uzh.ch/ayoub/PDF-Files/GaloisMotivic-1.pdf) $H$, but only in the homotopy category of $D(\mathbb Q)$, which is not enough to define $\tilde R$. 


Let me now assume that $k\subset \mathbb C$ and that $R$ is the Betti realization. Ayoub then proves that $H$ is connective, so that $\tau\_{\leq 0}H$ is a Hopf algebra in rational vector spaces. If $G^{cl}=\operatorname{Spec}(\tau\_{\leq 0}H)$, we then have a closed immersion $i\colon G^{cl}\hookrightarrow G$, whence


$$
i^\*\circ \tilde R: \operatorname{DM}\_{gm}(k)\_{\mathbb Q} \to \operatorname{Rep}\_{D\_c(\mathbb Q)}(G^{cl}).
$$


Choudhury and Gallauer Alves de Souza [proved](https://arxiv.org/pdf/1410.6104v2.pdf) that the group scheme $G^{cl}$ is isomorphic to Nori's motivic Galois group. 


The strongest conjecture one can make here is that $i^\*\circ\tilde R$ is an equivalence of ∞-categories. This conjecture is equivalent to the conjunction of two conjectures: $\tilde R$ is an equivalence, and $G^{cl}=G$. It also clearly implies the conservativity conjecture (that $R$ is conservative) and the existence of the motivic $t$-structure. Conversely, the existence of a $t$-structure such that $R$ is $t$-exact implies that $G^{cl}=G$. The conservativity of $R$ together with the existence of a suitable $t$-structure should imply that $\tilde R$ is an equivalence, but I cannot find an applicable reference at the moment.


