Vertical space after Bibliography name

Question

I am using Bibtex and need to change (smaller size) between bibliography name and authors names. The document class is report and I am using the natbib package.

\documentclass[11pt,notitlepage,a4paper,oneside]{report}
\usepackage[english]{babel}
\usepackage[cp1250]{inputenc}
\usepackage{graphicx}
\usepackage{amsmath,amsthm,amssymb,}
\usepackage{a4wide,eucal,exscale}
\usepackage{china2e,variore‌​f,acronym}
\usepackage[left=3.5cm,top=2cm,right=2cm,bottom=1cm]{geometry} 
\usepackage[round]{natbib}
\usepackage{fix-cm}
\usepackage{etoolbox}
\usepackage[Glenn]{fncychap}

Answer 1

The spacing between the title (Bibliography) and the items is exactly the same as in the other chapters.

Here is a way to reduce it, but I don't recommend doing it:

\documentclass[a4paper]{report}
\usepackage{natbib}
\usepackage{etoolbox}

\usepackage{lipsum} % only for the example
\begin{document}
\chapter{First chapter}

\lipsum[1]\nocite{*}

%%% Start of the bibliography    
\makeatletter
\patchcmd{\@makeschapterhead}{\vskip40}{\vskip10}{}{} % change 10 to something else, if you prefer
\makeatother

\bibliographystyle{plainnat}
\bibliography{jane}

\end{document}

This assuming you don't have any other unnumbered chapter afterwards.

The \chapter command relies on two macros for actually typesetting the chapter heading, \@makechapterhead for \chapter and \@makeschapterhead for \chapter*. Here are the definitions in the report class:

\def\@makechapterhead#1{%
  \vspace*{50\p@}%
  {\parindent \z@ \raggedright \normalfont
    \ifnum \c@secnumdepth >\m@ne
        \huge\bfseries \@chapapp\space \thechapter
        \par\nobreak
        \vskip 20\p@
    \fi
    \interlinepenalty\@M
    \Huge \bfseries #1\par\nobreak
    \vskip 40\p@
  }}
\def\@makeschapterhead#1{%
  \vspace*{50\p@}%
  {\parindent \z@ \raggedright
    \normalfont
    \interlinepenalty\@M
    \Huge \bfseries  #1\par\nobreak
    \vskip 40\p@
  }}

If you want to get rid of the space before the chapter heading and the space below, the best thing is to redefine them:

\makeatletter
\def\@makechapterhead#1{%
  \vspace*{-40\p@}%
  {\parindent \z@ \raggedright \normalfont
    \ifnum \c@secnumdepth >\m@ne
        \huge\bfseries \@chapapp\space \thechapter
        \par\nobreak
        \vskip 20\p@
    \fi
    \interlinepenalty\@M
    \Huge \bfseries #1\par\nobreak
    \vskip 12\p@
  }}
\def\@makeschapterhead#1{%
  \vspace*{-40\p@}%
  {\parindent \z@ \raggedright
    \normalfont
    \interlinepenalty\@M
    \Huge \bfseries  #1\par\nobreak
    \vskip 12\p@
  }}
\makeatother

Adjust the 12\p@ (which is equivalent to 12pt) to your needs.

However, this is not recommendable. Some space is needed because of the large font size used for the chapter title. If you want to reduce the space you have also to reduce the font size.

Play with the distances until you're satisfied.

Note for fncychap users.

You can obtain a reduction of the spaces by

\usepackage[Glenn]{fncychap}
\usepackage{etoolbox}
\makeatletter
\patchcmd{\DOTIS}{40\p@}{-10\p@}{}{}
\patchcmd{\DOTI}{80\p@}{20\p@}{}{}
\patchcmd{\@makechapterhead}{50\p@}{-20\p@}{}{}
\patchcmd{\@makeschapterhead}{50\p@}{-20\p@}{}{}
\makeatother

but I strongly advise against using such a chapter style, which is, in my opinion, one of the worst ever designed. Only Lenny is possibly worse.