def et_display_label(lower_label: str = "T", upper_label: str = "") -> str:
    """ Generate a E_T display label without the "$".

    Args:
        lower_label: Subscript label for E_T. Default: "T"
        upper_label: Superscript label for E_T. Default: ""
    Returns:
        Properly formatted E_T string.
    """
    return r"E_{\text{%(lower_label)s}}^{\text{%(upper_label)s}}" % {
        "lower_label": lower_label,
        "upper_label": upper_label,
    }