如何在Rmarkdown中正确格式化摘要（LaTeX转PDF）

问题根源是LaTeX的abstract环境默认会给第一段添加首段缩进，而后续段落自动取消缩进。你的写法中，Premise所在行作为摘要第一段触发了默认缩进，后面两行被识别为新段落，因此显示正常。

以下是两种可行的解决方法：

方法一：手动取消首段缩进 #

在摘要开头添加LaTeX命令\noindent，直接取消首段的缩进效果：

abstract: | 
  \noindent **Premise:** We did stuff.     
  **Methods and Results:** We used and developed stuff to accomplish stuff.       
  **Conclusions:** You too can do stuff.     

方法二：全局修改摘要环境设置 #

如果需要统一调整所有摘要的格式，可通过header-includes添加LaTeX命令，全局取消abstract环境的段落缩进：

--- 
title: 'A few people may read this thing'
author:  | 
    |  $^1$Research Institute    
    |  $^2$University  
    | Person$^1$^[Author for Correspondence: human@place.org], Other Person$^1$$^,$$^2$
abstract: | 
  **Premise:** We did stuff.     
  **Methods and Results:** We used and developed stuff to accomplish stuff.       
  **Conclusions:** You too can do stuff.     
keywords: |
  rmarkdown, latex, weird indent in abstract   
output:
  pdf_document: default
header-includes:
  - \usepackage{etoolbox}
  - \AtBeginEnvironment{abstract}{\setlength{\parindent}{0pt}}
--- 

# Introduction

内容的提问来源于stack exchange，提问作者steppe