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Title: QCD equation of state at large baryon chemical potential
Plain: Supercomputer calculations of QCD work well at zero net density but fail at high density because of the sign problem (contributions of opposite sign that cancel almost exactly). Without a fix, the dense part of the phase diagram cannot be computed directly.
Precise: Compute the pressure $P(T,\mu_{B})$ and the chiral transition line of $2+1$-flavor QCD at physical quark masses for $\mu_{B}/T$ between 3 and 6 with controlled continuum extrapolation, despite the complex fermion determinant. Answer: $P$ and $T_{\mathrm{pc}}(\mu_{B})$ with percent-level uncertainty, by any method (reweighting, Taylor expansion, imaginary $\mu_{B}$, complex Langevin, Lefschetz thimbles) validated against established results at $\mu_{B}/T<2$.
Settled by: An algorithm with cost polynomial in the lattice volume, validated against established results at $\mu_B/T < 2$ and applied at $\mu_B/T = 3\ \text{to}\ 6$.
Kind: well-posed
Answer type: value
References: (empty)
Literature status: open
Status note: (empty)
Posed since: (empty)