The LaTeX command for dagger adjoint (†) is \dagger (adjoint / conjugate transpose).
\daggerWriting a paper? The table generator and the BibTeX cleaner are one click away, no account.
Write \dagger inside math mode, that is between $…$ for inline math or in a \[ … \] or equation block for display math. It is part of core LaTeX math, so no extra package is required.
The physics and siunitx packages offer shortcuts for many formulas, but \dagger works in plain LaTeX. In running text, outside math mode, the same sign is \textdagger. With unicode-math under XeLaTeX or LuaLaTeX, typing † in a formula gives the same symbol.
Open this example in the live preview: it renders as you type, with no compiler and no signup.
\langle \psi || \psi \rangle\langle \phi | \psi \rangle\rightleftharpoons\text{\AA}^\circ\mathrm{C}\infty\hbar\nabla\nabla^2\nabla \cdot\nabla \times\partial\dot{x}Physics symbols in LaTeX: the full table or search all 350+ LaTeX symbols.
Use \dagger in math mode; it needs no extra package. For example, $\dagger$.
None: \dagger is built into LaTeX, so no extra package is required.